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89 (number)
Encyclopedia
89 is the natural number
following 88
and preceding 90
.
, following 83
and preceding 97
. 89 is a Chen prime
. It is the smallest Sophie Germain prime
to start a Cunningham chain
of the first kind of six terms, {89, 179, 359, 719, 1439, 2879}. 89 is an Eisenstein prime
with no imaginary part and real part of the form
.
89 is a Fibonacci number
. The first few digits of its reciprocal coincide with the Fibonacci sequence due to the identity
89 is also a Markov number
, appearing in solutions to the Markov Diophantine equation with other odd-indexed Fibonacci numbers.
Although 89 is not a Lychrel number
in base 10, it is unusual that it takes 24 iterations of the reverse and add process to reach a palindrome. Among the known non-Lychrel numbers in the first 10000 integers, no other number requires that many or more iterations. The palindrome reached is also unusually large.
Eighty-nine is also:
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 88
88 (number)
88 is the natural number following 87 and preceding 89.- In mathematics :Eighty-Eight is a refactorable number, a primitive semiperfect number and an untouchable number...
and preceding 90
90 (number)
90 is the natural number preceded by 89 and followed by 91.- In mathematics :*Because 90 is the sum of its unitary divisors , it is a unitary perfect number, and because it is equal to the sum of a subset of its divisors, it is a semiperfect number. 90 is a pronic number. But it is also a...
.
In mathematics
Eighty-nine is the 24th prime numberPrime number
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2...
, following 83
83 (number)
83 is the natural number following 82 and preceding 84.-In mathematics:Eighty-three is the sum of three consecutive primes as well as the sum of five consecutive primes ....
and preceding 97
97 (number)
97 is the natural number following 96 and preceding 98.-In mathematics:97 is the 25th prime number , following 89 and preceding 101. 97 is a Proth prime as it is 3 × 25 + 1.The numbers 97, 907, 9007, 90007 and 900007 are happy primes...
. 89 is a Chen prime
Chen prime
A prime number p is called a Chen prime if p + 2 is either a prime or a product of two primes. The even number 2p + 2 therefore satisfies Chen's theorem....
. It is the smallest Sophie Germain prime
Sophie Germain prime
In number theory, a prime number p is a Sophie Germain prime if 2p + 1 is also prime. For example, 23 is a Sophie Germain prime because it is a prime and 2 × 23 + 1 = 47, and 47 is also a prime number...
to start a Cunningham chain
Cunningham chain
In mathematics, a Cunningham chain is a certain sequence of prime numbers. Cunningham chains are named after mathematician A. J. C. Cunningham. They are also called chains of nearly doubled primes....
of the first kind of six terms, {89, 179, 359, 719, 1439, 2879}. 89 is an Eisenstein prime
Eisenstein prime
In mathematics, an Eisenstein prime is an Eisenstein integerz = a + b\,\omega\qquadthat is irreducible in the ring-theoretic sense: its only Eisenstein divisors are the units , a + bω itself and its associates.The associates and the complex conjugate...
with no imaginary part and real part of the form
.89 is a Fibonacci number
Fibonacci number
In mathematics, the Fibonacci numbers are the numbers in the following integer sequence:0,\;1,\;1,\;2,\;3,\;5,\;8,\;13,\;21,\;34,\;55,\;89,\;144,\; \ldots\; ....
. The first few digits of its reciprocal coincide with the Fibonacci sequence due to the identity
89 is also a Markov number
Markov number
A Markov number or Markoff number is a positive integer x, y or z that is part of a solution to the Markov Diophantine equationx^2 + y^2 + z^2 = 3xyz,\,studied by .The first few Markov numbers are...
, appearing in solutions to the Markov Diophantine equation with other odd-indexed Fibonacci numbers.
Although 89 is not a Lychrel number
Lychrel number
A Lychrel number is a natural number which cannot form a palindrome through the iterative process of repeatedly reversing its base 10 digits and adding the resulting numbers. This process is called the 196-algorithm. The name "Lychrel" was coined by Wade VanLandingham—a rough anagram of his...
in base 10, it is unusual that it takes 24 iterations of the reverse and add process to reach a palindrome. Among the known non-Lychrel numbers in the first 10000 integers, no other number requires that many or more iterations. The palindrome reached is also unusually large.
In 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...
M89, a magnitude 11.5 elliptical galaxyElliptical galaxyAn elliptical galaxy is a galaxy having an approximately ellipsoidal shape and a smooth, nearly featureless brightness profile. They range in shape from nearly spherical to highly flat and in size from hundreds of millions to over one trillion stars...
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....
VirgoVirgo (constellation)Virgo is one of the constellations of the zodiac. Its name is Latin for virgin, and its symbol is . Lying between Leo to the west and Libra to the east, it is the second largest constellation in the sky...
. - 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 89NGC 89-See also:* Robert's Quartet...
, a magnitude 13.5 peculiarPeculiar galaxyA peculiar galaxy is a galaxy which is unusual in its size, shape, or composition. Peculiar galaxies come about as a result of interactions between galaxies, and they may contain atypical amounts of dust or gas, may have higher or lower surface brightness than a typical galaxy, or may have...
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 PhoenixPhoenix (constellation)Phoenix is a minor constellation in the southern sky. It is named after the Phoenix, a mythical bird. It is faint: there are only two stars in the whole constellation which are brighter than magnitude 5.0...
and a member of Robert's QuartetRobert's QuartetRobert's Quartet is a compact galaxy group approximately 160 million light-years away in the constellation Phoenix. It is a family of four very different galaxies in the process of colliding and merging. Its members are NGC 87, NGC 88, NGC 89 and NGC 92, discovered by John Herschel in the...
.
In other fields
- Part of the name of the baseball team Oklahoma City 89ers (1962–1997)
- The designation of Interstate 89Interstate 89Interstate 89 is an interstate highway in the New England region of the United States travelling between Bow, New Hampshire and Highgate Springs, Vermont. As with all odd-numbered primary interstates, I-89 is signed as a north–south highway...
, a freeway that runs from New HampshireNew HampshireNew Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
to VermontVermontVermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England... - The designation of U.S. Route 89U.S. Route 89U.S. Route 89 is a north–south United States Highway with two sections, and one former section. The southern section runs for 848 miles from Flagstaff, Arizona, to the southern entrance of Yellowstone National Park...
, a north-south highway that runs from MontanaMontanaMontana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
to ArizonaArizonaArizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix... - The ISBN Group Identifier for books published in KoreaKoreaKorea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
- Pop Song 89Pop Song 89"Pop Song 89" was the third single released from R.E.M.'s sixth studio album Green. It peaked at #86 on the Hot 100, and in the UK "Stand" was re-released instead....
- The year AD 8989Year 89 was a common year starting on Thursday of the Julian calendar. At the time, it was known as the Year of the Consulship of Fulvus and Atratinus...
, 89 BC89 BCYear 89 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Strabo and Cato... - California Proposition 89, a 2006 California ballot initiative on campaign finance reform
- The Oklahoma RedhawksOklahoma RedHawksThe Oklahoma City RedHawks are a minor league baseball team based in Oklahoma City, Oklahoma. The team, which plays in the Pacific Coast League, is the Triple-A affiliate of the Houston Astros...
were formerly known as the Oklahoma 89ers. - In Rugby, an "89" or eight-nine move is a phase following a scrum, in which the number 8 catches the ball and transfers it to number 9 (scrum half).
- The greatest number of verses in a chapter of a book of the Bible other than the Book of Psalms—specifically NumbersBook of NumbersThe Book of Numbers is the fourth book of the Hebrew Bible, and the fourth of five books of the Jewish Torah/Pentateuch....
chapter 7. - The number of units of each colour in the board game BlokusBlokusBlokus is an abstract strategy board game for two to four players, invented by Bernard Tavitian and first released in 2000 by Sekkoïa, a French company. It has won several awards, including the Mensa Select award and the 2004 Teacher's Choice Award....
- The number of the French department YonneYonneYonne is a French department named after the Yonne River. It is one of the four constituent departments of Burgundy in eastern France and its prefecture is Auxerre. Its official number is 89....
- Information Is Beautiful cites eighty-nineTiananmen Square protests of 1989The Tiananmen Square protests of 1989, also known as the June Fourth Incident in Chinese , were a series of demonstrations in and near Tiananmen Square in Beijing in the People's Republic of China beginning on 15 April 1989...
as one of the words censored on the ChineseChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
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