256859631 has 12 divisors (see below), whose sum is σ = 424022352. Its totient is φ = 146776896.

The previous prime is 256859623. The next prime is 256859633. The reversal of 256859631 is 136958652.

256859631 is a `hidden beast` number, since 2 + 5 + 6 + 8 + 5 + 9 + 631 = 666.

It is not a de Polignac number, because 256859631 - 2³ = 256859623 is a prime.

It is a super-2 number, since 2×256859631² = 131953740074912322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256859633) 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, 2038506 + ... + 2038631.

It is an arithmetic number, because the mean of its divisors is an integer number (35335196).

Almost surely, 2^256859631 is an apocalyptic number.

256859631 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

256859631 is a deficient number, since it is larger than the sum of its proper divisors (167162721).

256859631 is a wasteful number, since it uses less digits than its factorization.

256859631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4077150 (or 4077147 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The square root of 256859631 is about 16026.8409550978. The cubic root of 256859631 is about 635.6703450623.

The spelling of 256859631 in words is "two hundred fifty-six million, eight hundred fifty-nine thousand, six hundred thirty-one".