11638878531 has 64 divisors (see below), whose sum is σ = 19293880320. Its totient is φ = 6094408320.

The previous prime is 11638878529. The next prime is 11638878541. The reversal of 11638878531 is 13587883611.

It is not a de Polignac number, because 11638878531 - 2¹ = 11638878529 is a prime.

It is a super-2 number, since 2×11638878531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11638878541) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1831746 + ... + 1838088.

It is an arithmetic number, because the mean of its divisors is an integer number (301466880).

Almost surely, 2^11638878531 is an apocalyptic number.

11638878531 is a deficient number, since it is larger than the sum of its proper divisors (7655001789).

11638878531 is a wasteful number, since it uses less digits than its factorization.

11638878531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6536.

The product of its digits is 967680, while the sum is 51.

The spelling of 11638878531 in words is "eleven billion, six hundred thirty-eight million, eight hundred seventy-eight thousand, five hundred thirty-one".