18220904 has 24 divisors (see below), whose sum is σ = 36997110. Its totient is φ = 8409024.

The previous prime is 18220897. The next prime is 18220919. The reversal of 18220904 is 40902281.

It can be written as a sum of positive squares in 3 ways, for example, as 10876804 + 7344100 = 3298^2 + 2710^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5387 + ... + 8090.

Almost surely, 2^18220904 is an apocalyptic number.

It is an amenable number.

18220904 is an abundant number, since it is smaller than the sum of its proper divisors (18776206).

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

18220904 is a wasteful number, since it uses less digits than its factorization.

18220904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13509 (or 13492 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 18220904 is about 4268.5950850368. The cubic root of 18220904 is about 263.1418801033.

The spelling of 18220904 in words is "eighteen million, two hundred twenty thousand, nine hundred four".