31318956 has 72 divisors (see below), whose sum is σ = 82882800. Its totient is φ = 9959040.

The previous prime is 31318943. The next prime is 31318961. The reversal of 31318956 is 65981313.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 31318956.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 136650 + ... + 136878.

It is an arithmetic number, because the mean of its divisors is an integer number (1151150).

Almost surely, 2^31318956 is an apocalyptic number.

31318956 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31318956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41441400).

31318956 is an abundant number, since it is smaller than the sum of its proper divisors (51563844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31318956 is a wasteful number, since it uses less digits than its factorization.

31318956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399 (or 394 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 31318956 is about 5596.3341572855. The cubic root of 31318956 is about 315.2117699187.

The spelling of 31318956 in words is "thirty-one million, three hundred eighteen thousand, nine hundred fifty-six".