18917968 has 20 divisors (see below), whose sum is σ = 36797248. Its totient is φ = 9421920.

The previous prime is 18917959. The next prime is 18917981. The reversal of 18917968 is 86971981.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2155 + ... + 6517.

Almost surely, 2^18917968 is an apocalyptic number.

It is an amenable number.

18917968 is a deficient number, since it is larger than the sum of its proper divisors (17879280).

18917968 is a wasteful number, since it uses less digits than its factorization.

18917968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4642 (or 4636 counting only the distinct ones).

The product of its digits is 217728, while the sum is 49.

The square root of 18917968 is about 4349.4790492656. The cubic root of 18917968 is about 266.4555857400.

The spelling of 18917968 in words is "eighteen million, nine hundred seventeen thousand, nine hundred sixty-eight".