256809101913 has 32 divisors (see below), whose sum is σ = 468255916800. Its totient is φ = 135459744768.

The previous prime is 256809101911. The next prime is 256809101933. The reversal of 256809101913 is 319101908652.

It is not a de Polignac number, because 256809101913 - 2¹ = 256809101911 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (256809101911) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52258248 + ... + 52263161.

It is an arithmetic number, because the mean of its divisors is an integer number (14632997400).

Almost surely, 2^256809101913 is an apocalyptic number.

It is an amenable number.

256809101913 is a deficient number, since it is larger than the sum of its proper divisors (211446814887).

256809101913 is a wasteful number, since it uses less digits than its factorization.

256809101913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104521438 (or 104521432 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The spelling of 256809101913 in words is "two hundred fifty-six billion, eight hundred nine million, one hundred one thousand, nine hundred thirteen".