256555031 has 4 divisors (see below), whose sum is σ = 256591200. Its totient is φ = 256518864.

The previous prime is 256555027. The next prime is 256555063. The reversal of 256555031 is 130555652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256555031 - 2² = 256555027 is a prime.

It is a super-2 number, since 2×256555031² = 131640967862821922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256555331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3551 + ... + 22928.

It is an arithmetic number, because the mean of its divisors is an integer number (64147800).

Almost surely, 2^256555031 is an apocalyptic number.

256555031 is a deficient number, since it is larger than the sum of its proper divisors (36169).

256555031 is an equidigital number, since it uses as much as digits as its factorization.

256555031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36168.

The product of its (nonzero) digits is 22500, while the sum is 32.

The square root of 256555031 is about 16017.3353277004. The cubic root of 256555031 is about 635.4189732989.

The spelling of 256555031 in words is "two hundred fifty-six million, five hundred fifty-five thousand, thirty-one".