18904 has 16 divisors (see below), whose sum is σ = 37800.
Its totient is φ = 8832.
The previous prime is 18899. The next prime is 18911. The reversal of 18904 is 40981.
It is a super-2 number, since 2×189042 = 714722432, which contains 22 as substring.
It is a congruent number.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67 + ... + 205.
218904 is an apocalyptic number.
It is an amenable number.
18904 is a deficient number, since it is larger than the sum of its proper divisors (18896).
18904 is a wasteful number, since it uses less digits than its factorization.
18904 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 162 (or 158 counting only the distinct ones).
The product of its (nonzero) digits is 288, while the sum is 22.
The square root of 18904 is about 137.4918179384.
The cubic root of 18904 is about 26.6389990816.
The spelling of 18904 in words is "eighteen thousand, nine hundred four".