256746917 has 12 divisors (see below), whose sum is σ = 299379276. Its totient is φ = 219542400.

The previous prime is 256746911. The next prime is 256747021. The reversal of 256746917 is 719647652.

It can be written as a sum of positive squares in 2 ways, for example, as 169156036 + 87590881 = 13006^2 + 9359^2 .

It is not a de Polignac number, because 256746917 - 2²² = 252552613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256746911) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15167 + ... + 27267.

It is an arithmetic number, because the mean of its divisors is an integer number (24948273).

Almost surely, 2^256746917 is an apocalyptic number.

It is an amenable number.

256746917 is a deficient number, since it is larger than the sum of its proper divisors (42632359).

256746917 is a wasteful number, since it uses less digits than its factorization.

256746917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12548 (or 12541 counting only the distinct ones).

The product of its digits is 635040, while the sum is 47.

The square root of 256746917 is about 16023.3241557425. The cubic root of 256746917 is about 635.5773507813.

The spelling of 256746917 in words is "two hundred fifty-six million, seven hundred forty-six thousand, nine hundred seventeen".