65 (number)
Encyclopedia
65 is the natural number
following 64
and preceding 66
.
and the 3rd of the form (5.q)it is an octagonal number. It is also a Cullen number
. Given 65, the Mertens function returns 0
.
Sixty-five has an aliquot sum of 19 and is the first composite number in the 19-aliquot tree.
This number is the magic constant
of 5 by 5 normal magic square
:
This number is also the magic constant
of n-Queens Problem
for n = 5.
65 is the smallest integer that can be expressed as a sum of two distinct positive squares in two ways, 65 = 82 + 12 = 72 + 42.
It appears in the Padovan sequence
, preceded by the terms 28, 37, 49 (it is the sum of the first two of these).
There are only 65 known Euler's idoneal numbers.
65=15+24+33+42+51
Natural number
In mathematics, the natural numbers are the ordinary whole numbers used for counting and ordering . These purposes are related to the linguistic notions of cardinal and ordinal numbers, respectively...
following 64
64 (number)
64 is the natural number following 63 and preceding 65.-In mathematics:Sixty-four is the square of 8, the cube of 4, and the sixth power of 2. It is the smallest number with exactly seven divisors. It is the lowest positive power of two that is adjacent to neither a Mersenne prime nor a Fermat...
and preceding 66
66 (number)
66 is the natural number following 65 and preceding 67.Usages of this number include:-Mathematics:*66 is a sphenic number, a triangular number, a hexagonal number, and a semi-meandric number...
.
In mathematics
Sixty-five is the 23rd semiprimeSemiprime
In mathematics, a semiprime is a natural number that is the product of two prime numbers. The first few semiprimes are 4, 6, 9, 10, 14, 15, 21, 22, 25, 26, ... ....
and the 3rd of the form (5.q)it is an octagonal number. It is also a Cullen number
Cullen number
In mathematics, a Cullen number is a natural number of the form n · 2n + 1 . Cullen numbers were first studied by Fr. James Cullen in 1905...
. Given 65, the Mertens function returns 0
0 (number)
0 is both a numberand the numerical digit used to represent that number in numerals.It fulfills a central role in mathematics as the additive identity of the integers, real numbers, and many other algebraic structures. As a digit, 0 is used as a placeholder in place value systems...
.
Sixty-five has an aliquot sum of 19 and is the first composite number in the 19-aliquot tree.
This number is the magic constant
Magic constant
The magic constant or magic sum of a magic square is the sum of numbers in any row, column, and diagonal of the magic square. For example, the magic square shown below has a magic constant of 15....
of 5 by 5 normal magic square
Magic square
In recreational mathematics, a magic square of order n is an arrangement of n2 numbers, usually distinct integers, in a square, such that the n numbers in all rows, all columns, and both diagonals sum to the same constant. A normal magic square contains the integers from 1 to n2...
:
This number is also the magic constant
Magic constant
The magic constant or magic sum of a magic square is the sum of numbers in any row, column, and diagonal of the magic square. For example, the magic square shown below has a magic constant of 15....
of n-Queens Problem
Eight queens puzzle
The eight queens puzzle is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens attack each other. Thus, a solution requires that no two queens share the same row, column, or diagonal...
for n = 5.
65 is the smallest integer that can be expressed as a sum of two distinct positive squares in two ways, 65 = 82 + 12 = 72 + 42.
It appears in the Padovan sequence
Padovan sequence
The Padovan sequence is the sequence of integers P defined by the initial valuesP=P=P=1,and the recurrence relationP=P+P.The first few values of P are...
, preceded by the terms 28, 37, 49 (it is the sum of the first two of these).
There are only 65 known Euler's idoneal numbers.
65=15+24+33+42+51
Astronomy
- Messier objectMessier objectThe Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. The original motivation of the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets...
M65M65M65 or M-65 may refer to:* Iveco LMV, an Italian-designed four-wheel drive tactical vehicle in service with several countries* M 65 105mm Recoilless Rifle, a Yugoslavian recoilless rifle* M-65 , a Michigan state highway...
, a magnitude 10.5 galaxyGalaxyA galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
in the constellationConstellationIn modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
LeoLeo (constellation)Leo is one of the constellations of the zodiac. Its name is Latin for lion. Its symbol is . Leo lies between dim Cancer to the west and Virgo to the east.-Stars:...
- The New General CatalogueNew General CatalogueThe New General Catalogue of Nebulae and Clusters of Stars is a well-known catalogue of deep sky objects in astronomy. It contains 7,840 objects, known as the NGC objects...
object NGC 65, a spiral galaxySpiral galaxyA spiral galaxy is a certain kind of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as...
in the constellation CetusCetusCetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not...
- The Saros number of the solar eclipseSolar eclipseAs seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...
series which began on -749 April 24 and ended on 513 May. The duration of Saros series 65 was 1262.1 years, and it contained 71 solar eclipses.
- The Saros number of the lunar eclipseLunar eclipseA lunar eclipse occurs when the Moon passes behind the Earth so that the Earth blocks the Sun's rays from striking the Moon. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur the night of a...
series which began on -736 August 11 and ended on 797 February. The duration of Saros series 65 was 1532.5 years, and it contained 86 lunar eclipses.
In music
- "65 Love Affair", singer Paul Davis' hit song in 1982
- Sammy HagarSammy HagarSam Roy "Sammy" Hagar , also known as The Red Rocker, is an American rock singer, guitarist, and songwriter. Also sings Country Music....
re-recorded his hit "I Can't Drive 55", with the 55 changed to 65, in 2001 for NBC's NASCAR broadcasts to reflect higher speed limits; the song was used from 2001 until 2004 to introduce Budweiser Pole Award winners on NBC and TNT broadcasts - 65 is a commonly used abbreviation for the Sheffield, UK, post-rock band 65daysofstatic65daysofstatic65daysofstatic are an instrumental post-rock and math rock band from Sheffield, England comprising Paul Wolinski, Joe Shrewsbury, Rob Jones and Simon Wright...
- Referenced in "Heroes and VillainsHeroes and Villains"Heroes and Villains" is a song by the American rock band The Beach Boys, co-written by the group's leader Brian Wilson and lyricist Van Dyke Parks. Originally intended by Wilson to be the centerpiece of the ambitious but shelved album Smile, a re-recorded version of the song was released on Smiley...
" by the Beach Boys: "At 60 and 5 / I'm very much alive / I've still got the jive / to survive with the Heroes and Villains"
In other fields
Sixty-five is:- A common speed limitSpeed limitRoad speed limits are used in most countries to regulate the speed of road vehicles. Speed limits may define maximum , minimum or no speed limit and are normally indicated using a traffic sign...
, in miles per hour, for freeways in many U.S.United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
states, primarily in the eastern United States (in the western United States, the common limit is 70 and in some places 75) - The designation of Interstate 65Interstate 65Interstate 65 is a major Interstate Highway in the United States. The southern terminus is located at an intersection with Interstate 10 in Mobile, Alabama, and its northern terminus is at an interchange with Interstate 90 , U.S. Route 12, and U.S...
, a freeway that runs from AlabamaAlabamaAlabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
to IndianaIndianaIndiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is... - Municipal Okrug 65, a municipal okrug of Primorsky District of Saint PetersburgSaint PetersburgSaint Petersburg is a city and a federal subject of Russia located on the Neva River at the head of the Gulf of Finland on the Baltic Sea...
, Russia - +65 is the code for international direct dial phone calls to SingaporeSingaporeSingapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
- The traditional age for retirementRetirementRetirement is the point where a person stops employment completely. A person may also semi-retire by reducing work hours.Many people choose to retire when they are eligible for private or public pension benefits, although some are forced to retire when physical conditions don't allow the person to...
in the United KingdomUnited KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, GermanyGermanyGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
and other countries. It was previously the age at which a person in the United StatesUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
could retire with full Social SecuritySocial Security (United States)In the United States, Social Security refers to the federal Old-Age, Survivors, and Disability Insurance program.The original Social Security Act and the current version of the Act, as amended encompass several social welfare and social insurance programs...
benefits; however, recent changes in the law have increased this age for younger workers due to improvements in life expectancy - The registry of the U.S. Navy's nuclear aircraft carrier USS Enterprise (CVN-65)USS Enterprise (CVN-65)USS Enterprise , formerly CVA-65, is the world's first nuclear-powered aircraft carrier and the eighth US naval vessel to bear the name. Like her predecessor of World War II fame, she is nicknamed the "Big E". At , she is the longest naval vessel in the world...
- 65 is the minimum grade required to pass an exam, or class, in many areas
- The setting of Naked CityNaked City (TV series)Naked City is a police drama series which aired from 1958 to 1963 on the ABC television network. It was inspired by the 1948 motion picture of the same name, and mimics its dramatic "semi-documentary" format....
(1958 - 63) was New York's 65th Precinct - The number of the French department Hautes-PyrénéesHautes-PyrénéesHautes-Pyrénées is a department in southwestern France. It is part of the Midi-Pyrénées region.-History:...
- 65 is commonly used in names of many dishes of South IndiaSouth IndiaSouth India is the area encompassing India's states of Andhra Pradesh, Karnataka, Kerala and Tamil Nadu as well as the union territories of Lakshadweep and Pondicherry, occupying 19.31% of India's area...
cuisine, for instance Chicken 65Chicken 65Chicken 65 is a spicy, deep-fried chicken dish popular in South India, as a bar snack, entree, or quick snack. The flavour of the dish comes from ginger, cayenne pepper, mustard powder and vinegar although the exact recipe can vary...