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|Cardinal||two hundred fifteen|
(two hundred and fifteenth)
|Factorization||5 × 43|
- 215 is a composite number and a semiprime.
- 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 is a Main belt asteroid.
- E215 is the E number of Sodium ethyl para-hydroxybenzoate.
- There are several highways numbered 215.
215 is also:
- The Dewey Decimal Classification for Science and religion.
- The year AD 215 or 215 BC
- 215 is often used as slang for marijuana, from California Proposition 215, legalizing it for medical use.
- The first area code of metropolitan Philadelphia, Pennsylvania
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