18681972 has 24 divisors (see below), whose sum is σ = 44118816. Its totient is φ = 6151968.

The previous prime is 18681967. The next prime is 18681989. The reversal of 18681972 is 27918681.

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, 8383 + ... + 10374.

It is an arithmetic number, because the mean of its divisors is an integer number (1838284).

Almost surely, 2^18681972 is an apocalyptic number.

18681972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18681972 is an abundant number, since it is smaller than the sum of its proper divisors (25436844).

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

18681972 is a wasteful number, since it uses less digits than its factorization.

18681972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18847 (or 18845 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 18681972 is about 4322.2646841673. The cubic root of 18681972 is about 265.3429616690.

The spelling of 18681972 in words is "eighteen million, six hundred eighty-one thousand, nine hundred seventy-two".