256931572417 has 4 divisors (see below), whose sum is σ = 276695539540. Its totient is φ = 237167605296.

The previous prime is 256931572343. The next prime is 256931572439. The reversal of 256931572417 is 714275139652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 125571718321 + 131359854096 = 354361^2 + 362436^2 .

It is a cyclic number.

It is not a de Polignac number, because 256931572417 - 2¹⁵ = 256931539649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256931572477) 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, 9881983542 + ... + 9881983567.

It is an arithmetic number, because the mean of its divisors is an integer number (69173884885).

Almost surely, 2^256931572417 is an apocalyptic number.

It is an amenable number.

256931572417 is a deficient number, since it is larger than the sum of its proper divisors (19763967123).

256931572417 is a wasteful number, since it uses less digits than its factorization.

256931572417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19763967122.

The product of its digits is 3175200, while the sum is 52.

The spelling of 256931572417 in words is "two hundred fifty-six billion, nine hundred thirty-one million, five hundred seventy-two thousand, four hundred seventeen".