18664428 has 48 divisors (see below), whose sum is σ = 45215744. Its totient is φ = 5987520.

The previous prime is 18664417. The next prime is 18664433. The reversal of 18664428 is 82446681.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56223 + ... + 56553.

Almost surely, 2^18664428 is an apocalyptic number.

It is an amenable number.

18664428 is an abundant number, since it is smaller than the sum of its proper divisors (26551316).

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

18664428 is a wasteful number, since it uses less digits than its factorization.

18664428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502 (or 500 counting only the distinct ones).

The product of its digits is 73728, while the sum is 39.

The square root of 18664428 is about 4320.2347158459. The cubic root of 18664428 is about 265.2598755992.

The spelling of 18664428 in words is "eighteen million, six hundred sixty-four thousand, four hundred twenty-eight".