Fifteen (15, XV) is the natural number following fourteen and preceding sixteen.
Mathematics
Fifteen is a triangular number and the 4th Bell number. It is a composite number; its proper divisors being 1, 3 and 5.
In hexadecimal, as well as all higher bases, fifteen is represented as F.
Fifteen is the magic result of a 3 by 3 magic square:
Other fields
Fifteen is:
- The atomic number of phosphorous.
- The number of guns in a gun salute to Army, Air Force and Marine Corps Lieutenant Generals, and Navy and Coast Guard Vice Admirals.
- The designation of Interstate 15, a freeway that runs from California to Montana.
- The age of a quinceañera, a Hispanic girl celebrating her fifteenth birthday.
- The age for obtaining a driver's permit in jurisdictions where the age for a driver's license is sixteen.
- The number of players on a rugby union team.
- Fifteen, a television program.
- The year AD 15.
14 and 16
