256817772315 has 128 divisors (see below), whose sum is σ = 500563795200. Its totient is φ = 124157214720.

The previous prime is 256817772307. The next prime is 256817772361. The reversal of 256817772315 is 513277718652.

256817772315 is a `hidden beast` number, since 2 + 568 + 1 + 7 + 7 + 72 + 3 + 1 + 5 = 666.

It is not a de Polignac number, because 256817772315 - 2³ = 256817772307 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 81039051 + ... + 81042219.

It is an arithmetic number, because the mean of its divisors is an integer number (3910654650).

Almost surely, 2^256817772315 is an apocalyptic number.

256817772315 is a deficient number, since it is larger than the sum of its proper divisors (243746022885).

256817772315 is a wasteful number, since it uses less digits than its factorization.

256817772315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4014 (or 4008 counting only the distinct ones).

The product of its digits is 4939200, while the sum is 54.

The spelling of 256817772315 in words is "two hundred fifty-six billion, eight hundred seventeen million, seven hundred seventy-two thousand, three hundred fifteen".