256667568 has 20 divisors (see below), whose sum is σ = 663058008. Its totient is φ = 85555840.

The previous prime is 256667539. The next prime is 256667591. The reversal of 256667568 is 865766652.

It is a self number, because there is not a number n which added to its sum of digits gives 256667568.

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, 2673573 + ... + 2673668.

Almost surely, 2^256667568 is an apocalyptic number.

It is an amenable number.

256667568 is an abundant number, since it is smaller than the sum of its proper divisors (406390440).

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

256667568 is a wasteful number, since it uses less digits than its factorization.

256667568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5347252 (or 5347246 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 51.

The square root of 256667568 is about 16020.8479176353. The cubic root of 256667568 is about 635.5118678482.

The spelling of 256667568 in words is "two hundred fifty-six million, six hundred sixty-seven thousand, five hundred sixty-eight".