18938864 has 20 divisors (see below), whose sum is σ = 41936304. Its totient is φ = 8116608.

The previous prime is 18938863. The next prime is 18938879. The reversal of 18938864 is 46883981.

It is a super-2 number, since 2×18938864² = 717361139220992, which contains 22 as substring.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18938863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84437 + ... + 84660.

Almost surely, 2^18938864 is an apocalyptic number.

18938864 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

18938864 is an abundant number, since it is smaller than the sum of its proper divisors (22997440).

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

18938864 is a wasteful number, since it uses less digits than its factorization.

18938864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169112 (or 169106 counting only the distinct ones).

The product of its digits is 331776, while the sum is 47.

The square root of 18938864 is about 4351.8805130656. The cubic root of 18938864 is about 266.5536548908.

The spelling of 18938864 in words is "eighteen million, nine hundred thirty-eight thousand, eight hundred sixty-four".