256557995 has 12 divisors (see below), whose sum is σ = 315207216. Its totient is φ = 200466000.

The previous prime is 256557971. The next prime is 256557997. The reversal of 256557995 is 599755652.

It is not a de Polignac number, because 256557995 - 2⁸ = 256557739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256557997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4631 + ... + 23120.

It is an arithmetic number, because the mean of its divisors is an integer number (26267268).

Almost surely, 2^256557995 is an apocalyptic number.

256557995 is a deficient number, since it is larger than the sum of its proper divisors (58649221).

256557995 is an equidigital number, since it uses as much as digits as its factorization.

256557995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27842 (or 27799 counting only the distinct ones).

The product of its digits is 4252500, while the sum is 53.

The square root of 256557995 is about 16017.4278521865. The cubic root of 256557995 is about 635.4214203043.

The spelling of 256557995 in words is "two hundred fifty-six million, five hundred fifty-seven thousand, nine hundred ninety-five".