256581568 has 28 divisors (see below), whose sum is σ = 516138160. Its totient is φ = 126531072.

The previous prime is 256581551. The next prime is 256581581. The reversal of 256581568 is 865185652.

It is a happy number.

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, 22788 + ... + 32131.

Almost surely, 2^256581568 is an apocalyptic number.

It is an amenable number.

256581568 is an abundant number, since it is smaller than the sum of its proper divisors (259556592).

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

256581568 is an equidigital number, since it uses as much as digits as its factorization.

256581568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55004 (or 54994 counting only the distinct ones).

The product of its digits is 576000, while the sum is 46.

The square root of 256581568 is about 16018.1636900114. The cubic root of 256581568 is about 635.4408809209.

The spelling of 256581568 in words is "two hundred fifty-six million, five hundred eighty-one thousand, five hundred sixty-eight".