18663988 has 24 divisors (see below), whose sum is σ = 37497600. Its totient is φ = 7962528.

The previous prime is 18663941. The next prime is 18664007. The reversal of 18663988 is 88936681.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5298 + ... + 8086.

It is an arithmetic number, because the mean of its divisors is an integer number (1562400).

Almost surely, 2^18663988 is an apocalyptic number.

It is an amenable number.

18663988 is an abundant number, since it is smaller than the sum of its proper divisors (18833612).

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

18663988 is a wasteful number, since it uses less digits than its factorization.

18663988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3039 (or 3037 counting only the distinct ones).

The product of its digits is 497664, while the sum is 49.

The square root of 18663988 is about 4320.1837923866. The cubic root of 18663988 is about 265.2577911481.

The spelling of 18663988 in words is "eighteen million, six hundred sixty-three thousand, nine hundred eighty-eight".