18720116864 has 32 divisors (see below), whose sum is σ = 37509599340. Its totient is φ = 9305943040.

The previous prime is 18720116837. The next prime is 18720116867. The reversal of 18720116864 is 46861102781.

It can be written as a sum of positive squares in 2 ways, for example, as 18712051264 + 8065600 = 136792^2 + 2840^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (18720116867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400547 + ... + 444834.

Almost surely, 2^18720116864 is an apocalyptic number.

It is an amenable number.

18720116864 is an abundant number, since it is smaller than the sum of its proper divisors (18789482476).

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

18720116864 is an equidigital number, since it uses as much as digits as its factorization.

18720116864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845568 (or 845556 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 44.

The spelling of 18720116864 in words is "eighteen billion, seven hundred twenty million, one hundred sixteen thousand, eight hundred sixty-four".