18520817166 has 24 divisors (see below), whose sum is σ = 40134569904. Its totient is φ = 6172662240.

The previous prime is 18520817149. The next prime is 18520817213. The reversal of 18520817166 is 66171802581.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47935 + ... + 198341.

It is an arithmetic number, because the mean of its divisors is an integer number (1672273746).

Almost surely, 2^18520817166 is an apocalyptic number.

18520817166 is an abundant number, since it is smaller than the sum of its proper divisors (21613752738).

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

18520817166 is a wasteful number, since it uses less digits than its factorization.

18520817166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157256 (or 157253 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 18520817166 in words is "eighteen billion, five hundred twenty million, eight hundred seventeen thousand, one hundred sixty-six".