256767813 has 20 divisors (see below), whose sum is σ = 406131660. Its totient is φ = 161108352.

The previous prime is 256767683. The next prime is 256767829. The reversal of 256767813 is 318767652.

256767813 is a `hidden beast` number, since 2 + 567 + 6 + 7 + 81 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 94128804 + 162639009 = 9702^2 + 12753^2 .

It is not a de Polignac number, because 256767813 - 2⁸ = 256767557 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256767613) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 91858 + ... + 94611.

It is an arithmetic number, because the mean of its divisors is an integer number (20306583).

Almost surely, 2^256767813 is an apocalyptic number.

It is an amenable number.

256767813 is a deficient number, since it is larger than the sum of its proper divisors (149363847).

256767813 is a wasteful number, since it uses less digits than its factorization.

256767813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186498 (or 186489 counting only the distinct ones).

The product of its digits is 423360, while the sum is 45.

The square root of 256767813 is about 16023.9761919444. The cubic root of 256767813 is about 635.5945930060.

It can be divided in two parts, 25676 and 7813, that added together give a square (33489 = 183²).

The spelling of 256767813 in words is "two hundred fifty-six million, seven hundred sixty-seven thousand, eight hundred thirteen".