20431656 has 64 divisors (see below), whose sum is σ = 64867200. Its totient is φ = 5837184.

The previous prime is 20431639. The next prime is 20431661. The reversal of 20431656 is 65613402.

20431656 is a `hidden beast` number, since 2 + 0 + 4 + 3 + 1 + 656 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5245 + ... + 8268.

It is an arithmetic number, because the mean of its divisors is an integer number (1013550).

Almost surely, 2^20431656 is an apocalyptic number.

It is an amenable number.

20431656 is an abundant number, since it is smaller than the sum of its proper divisors (44435544).

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

20431656 is a wasteful number, since it uses less digits than its factorization.

20431656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13535 (or 13525 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 20431656 is about 4520.1389359178. The cubic root of 20431656 is about 273.3807030071.

The spelling of 20431656 in words is "twenty million, four hundred thirty-one thousand, six hundred fifty-six".