11817581256 has 96 divisors (see below), whose sum is σ = 35399615160. Its totient is φ = 3537893376.

The previous prime is 11817581239. The next prime is 11817581257. The reversal of 11817581256 is 65218571811.

11817581256 is a `hidden beast` number, since 1 + 1 + 8 + 17 + 581 + 2 + 56 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 9907017156 + 1910564100 = 99534^2 + 43710^2 .

It is not an unprimeable number, because it can be changed into a prime (11817581257) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135985 + ... + 205248.

Almost surely, 2^11817581256 is an apocalyptic number.

It is an amenable number.

11817581256 is an abundant number, since it is smaller than the sum of its proper divisors (23582033904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11817581256 is a wasteful number, since it uses less digits than its factorization.

11817581256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341295 (or 341288 counting only the distinct ones).

The product of its digits is 134400, while the sum is 45.

The spelling of 11817581256 in words is "eleven billion, eight hundred seventeen million, five hundred eighty-one thousand, two hundred fifty-six".