52 (number)
(Redirected from Number 52)
Template:Infobox number 52 (fifty-two) is the natural number following 51 and preceding 53.
In mathematics
Fifty-two is
- a composite number; a square-prime, of the form Template:Nobr where Template:Mvar is some prime larger than Template:Nobr It is the sixth of this form and the fifth of the form Template:Nobr
- the 5th Bell number,[1] the number of ways to partition a set of 5 objects.
- a decagonal number.[2]
- with an aliquot sum of 46; within an aliquot sequence of seven composite numbers Template:Math to the prime in the 3-aliquot tree. This sequence does not extend above 52 because it is,
- an untouchable number, since it is never the sum of proper divisors of any number. It is the first untouchable number larger than 2 and 5.[3]
- a noncototient since it is not equal to Template:Math for any Template:Nobr[4]
- a vertically symmetrical number.[5]
In other fields
Fifty-two is:
- The number of cards in a standard deck of playing cards, not counting Jokers or advertisement cards