256557855 has 32 divisors (see below), whose sum is σ = 433094400. Its totient is φ = 129330432.

The previous prime is 256557841. The next prime is 256557881. The reversal of 256557855 is 558755652.

It is not a de Polignac number, because 256557855 - 2²⁰ = 255509279 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 175116 + ... + 176574.

It is an arithmetic number, because the mean of its divisors is an integer number (13534200).

Almost surely, 2^256557855 is an apocalyptic number.

256557855 is a deficient number, since it is larger than the sum of its proper divisors (176536545).

256557855 is a wasteful number, since it uses less digits than its factorization.

256557855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2103.

The product of its digits is 2100000, while the sum is 48.

The square root of 256557855 is about 16017.4234819462. The cubic root of 256557855 is about 635.4213047241.

The spelling of 256557855 in words is "two hundred fifty-six million, five hundred fifty-seven thousand, eight hundred fifty-five".