In mathematics

• 215 is a composite number
  Composite number
  A composite number is a positive integer which has a positive divisor other than one or itself. In other words a composite number is any positive integer greater than one that is not a prime number....
  
   and a semiprime
  Semiprime
  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, ... ....
  
  .
• 
• 215 is the second smallest integer (after 5) such that is twice a square: .
• There are 215 sequences of four integers, counting re-arrangements as distinct, such that the sum of their reciprocals is 1. These are
  • 24 arrangements of (2,3,7,42), (2,3,8,24), (2,3,9,18), (2,3,10,15), (2,4,5,20) and (2,4,6,12).
  • 12 arrangements of (3,3,4,12), (3,4,4,6), (2,3,12,12), (2,4,8,8) and (2,5,5,10).
  • 6 arrangements of (3,3,6,6).
  • 4 arrangements of (2,6,6,6).
  • 1 arrangement of (4,4,4,4).

In other fields

• 215 Oenone
  215 Oenone
  215 Oenone is a typical Main belt asteroid.It was discovered by Viktor Knorre on April 7, 1880 in Berlin. It was first of his four asteroid discoveries.It was named after Oenone, a nymph in Greek mythology.- References :...
  
   is a Main belt
  Asteroid belt
  The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...
  
   asteroid
  Asteroid
  Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
  
  .
• E215 is the E number
  E number
  E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...
  
   of Sodium ethyl para-hydroxybenzoate.
• There are several highways numbered 215.

• The Dewey Decimal Classification
  Dewey Decimal Classification
  Dewey Decimal Classification, is a proprietary system of library classification developed by Melvil Dewey in 1876.It has been greatly modified and expanded through 23 major revisions, the most recent in 2011...
  
   for Science and religion.
• The year AD 215
  215
  Year 215 was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Laetus and Sulla...
  
  or 215 BC
  215 BC
  Year 215 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Albinus/Marcellus/Verrucosus and Gracchus...