18007911531 has 12 divisors (see below), whose sum is σ = 26012612808. Its totient is φ = 12004727424.

The previous prime is 18007911529. The next prime is 18007911539. The reversal of 18007911531 is 13511970081.

It is not a de Polignac number, because 18007911531 - 2¹ = 18007911529 is a prime.

It is a super-2 number, since 2×18007911531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18007911539) 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, 304336 + ... + 358658.

It is an arithmetic number, because the mean of its divisors is an integer number (2167717734).

Almost surely, 2^18007911531 is an apocalyptic number.

18007911531 is a deficient number, since it is larger than the sum of its proper divisors (8004701277).

18007911531 is a wasteful number, since it uses less digits than its factorization.

18007911531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91162 (or 91159 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 36.

The spelling of 18007911531 in words is "eighteen billion, seven million, nine hundred eleven thousand, five hundred thirty-one".