31920856 has 32 divisors (see below), whose sum is σ = 66200400. Its totient is φ = 14307840.

The previous prime is 31920841. The next prime is 31920859. The reversal of 31920856 is 65802913.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31920859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3940 + ... + 8908.

Almost surely, 2^31920856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31920856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33100200).

31920856 is an abundant number, since it is smaller than the sum of its proper divisors (34279544).

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

31920856 is a wasteful number, since it uses less digits than its factorization.

31920856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5059 (or 5055 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 31920856 is about 5649.8545114012. The cubic root of 31920856 is about 317.2182583404.

The spelling of 31920856 in words is "thirty-one million, nine hundred twenty thousand, eight hundred fifty-six".