256958865 has 32 divisors (see below), whose sum is σ = 464572800. Its totient is φ = 134717760.

The previous prime is 256958857. The next prime is 256958903. The reversal of 256958865 is 568859652.

256958865 is a `hidden beast` number, since 2 + 56 + 9 + 588 + 6 + 5 = 666.

It is not a de Polignac number, because 256958865 - 2³ = 256958857 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8166 + ... + 24095.

It is an arithmetic number, because the mean of its divisors is an integer number (14517900).

Almost surely, 2^256958865 is an apocalyptic number.

It is an amenable number.

256958865 is a deficient number, since it is larger than the sum of its proper divisors (207613935).

256958865 is a wasteful number, since it uses less digits than its factorization.

256958865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32334 (or 32328 counting only the distinct ones).

The product of its digits is 5184000, while the sum is 54.

The square root of 256958865 is about 16029.9365251395. The cubic root of 256958865 is about 635.7521952011.

The spelling of 256958865 in words is "two hundred fifty-six million, nine hundred fifty-eight thousand, eight hundred sixty-five".