18638764 has 24 divisors (see below), whose sum is σ = 34574400. Its totient is φ = 8776320.

The previous prime is 18638759. The next prime is 18638771. The reversal of 18638764 is 46783681.

It is a self number, because there is not a number n which added to its sum of digits gives 18638764.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2797 + ... + 6715.

It is an arithmetic number, because the mean of its divisors is an integer number (1440600).

Almost surely, 2^18638764 is an apocalyptic number.

It is an amenable number.

18638764 is a deficient number, since it is larger than the sum of its proper divisors (15935636).

18638764 is a wasteful number, since it uses less digits than its factorization.

18638764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3993 (or 3991 counting only the distinct ones).

The product of its digits is 193536, while the sum is 43.

The square root of 18638764 is about 4317.2634851257. The cubic root of 18638764 is about 265.1382404394.

The spelling of 18638764 in words is "eighteen million, six hundred thirty-eight thousand, seven hundred sixty-four".