256931427091 has 4 divisors (see below), whose sum is σ = 270454133800. Its totient is φ = 243408720384.

The previous prime is 256931427037. The next prime is 256931427131. The reversal of 256931427091 is 190724139652.

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 256931427091 - 2²⁵ = 256897872659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256931427691) 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, 6761353326 + ... + 6761353363.

It is an arithmetic number, because the mean of its divisors is an integer number (67613533450).

Almost surely, 2^256931427091 is an apocalyptic number.

256931427091 is a deficient number, since it is larger than the sum of its proper divisors (13522706709).

256931427091 is a wasteful number, since it uses less digits than its factorization.

256931427091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13522706708.

The product of its (nonzero) digits is 816480, while the sum is 49.

The spelling of 256931427091 in words is "two hundred fifty-six billion, nine hundred thirty-one million, four hundred twenty-seven thousand, ninety-one".