18615972 has 24 divisors (see below), whose sum is σ = 45724000. Its totient is φ = 5878656.

The previous prime is 18615937. The next prime is 18615977. The reversal of 18615972 is 27951681.

It is a self number, because there is not a number n which added to its sum of digits gives 18615972.

It is not an unprimeable number, because it can be changed into a prime (18615977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40597 + ... + 41052.

Almost surely, 2^18615972 is an apocalyptic number.

18615972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18615972 is an abundant number, since it is smaller than the sum of its proper divisors (27108028).

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

18615972 is a wasteful number, since it uses less digits than its factorization.

18615972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81675 (or 81673 counting only the distinct ones).

The product of its digits is 30240, while the sum is 39.

The square root of 18615972 is about 4314.6230426307. The cubic root of 18615972 is about 265.0301235484.

It can be divided in two parts, 186 and 15972, that multiplied together give a palindrome (2970792).

The spelling of 18615972 in words is "eighteen million, six hundred fifteen thousand, nine hundred seventy-two".