18981972 has 24 divisors (see below), whose sum is σ = 49212800. Its totient is φ = 6327288.

The previous prime is 18981961. The next prime is 18981997. The reversal of 18981972 is 27918981.

It is a super-2 number, since 2×18981972² = 720630522017568, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87772 + ... + 87987.

Almost surely, 2^18981972 is an apocalyptic number.

18981972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18981972 is an abundant number, since it is smaller than the sum of its proper divisors (30230828).

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

18981972 is a wasteful number, since it uses less digits than its factorization.

18981972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175772 (or 175764 counting only the distinct ones).

The product of its digits is 72576, while the sum is 45.

The square root of 18981972 is about 4356.8304993424. The cubic root of 18981972 is about 266.7557417706.

The spelling of 18981972 in words is "eighteen million, nine hundred eighty-one thousand, nine hundred seventy-two".