20856568 has 16 divisors (see below), whose sum is σ = 40455000. Its totient is φ = 10068576.

The previous prime is 20856551. The next prime is 20856599. The reversal of 20856568 is 86565802.

It is a self number, because there is not a number n which added to its sum of digits gives 20856568.

It is a congruent number.

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, 44718 + ... + 45181.

Almost surely, 2^20856568 is an apocalyptic number.

It is an amenable number.

20856568 is a deficient number, since it is larger than the sum of its proper divisors (19598432).

20856568 is a wasteful number, since it uses less digits than its factorization.

20856568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89934 (or 89930 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 40.

The square root of 20856568 is about 4566.8991668308. The cubic root of 20856568 is about 275.2628583091.

The spelling of 20856568 in words is "twenty million, eight hundred fifty-six thousand, five hundred sixty-eight".