18533867172 has 72 divisors (see below), whose sum is σ = 44902795392. Its totient is φ = 5949686400.

The previous prime is 18533867159. The next prime is 18533867207. The reversal of 18533867172 is 27176833581.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4347522 + ... + 4351782.

It is an arithmetic number, because the mean of its divisors is an integer number (623649936).

Almost surely, 2^18533867172 is an apocalyptic number.

18533867172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18533867172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22451397696).

18533867172 is an abundant number, since it is smaller than the sum of its proper divisors (26368928220).

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

18533867172 is a wasteful number, since it uses less digits than its factorization.

18533867172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4757 (or 4726 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 51.

The spelling of 18533867172 in words is "eighteen billion, five hundred thirty-three million, eight hundred sixty-seven thousand, one hundred seventy-two".