20931856 has 20 divisors (see below), whose sum is σ = 44242704. Its totient is φ = 9514400.

The previous prime is 20931809. The next prime is 20931877. The reversal of 20931856 is 65813902.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59290 + ... + 59641.

Almost surely, 2^20931856 is an apocalyptic number.

It is an amenable number.

20931856 is an abundant number, since it is smaller than the sum of its proper divisors (23310848).

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

20931856 is a wasteful number, since it uses less digits than its factorization.

20931856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118950 (or 118944 counting only the distinct ones).

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

The square root of 20931856 is about 4575.1345335411. The cubic root of 20931856 is about 275.5936750170.

The spelling of 20931856 in words is "twenty million, nine hundred thirty-one thousand, eight hundred fifty-six".