18218404 has 12 divisors (see below), whose sum is σ = 32134144. Its totient is φ = 9037224.

The previous prime is 18218401. The next prime is 18218411. The reversal of 18218404 is 40481281.

It is not an unprimeable number, because it can be changed into a prime (18218401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17424 + ... + 18439.

Almost surely, 2^18218404 is an apocalyptic number.

It is an amenable number.

18218404 is a deficient number, since it is larger than the sum of its proper divisors (13915740).

18218404 is a wasteful number, since it uses less digits than its factorization.

18218404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35994 (or 35992 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 18218404 is about 4268.3022385956. The cubic root of 18218404 is about 263.1298447548.

Adding to 18218404 its reverse (40481281), we get a palindrome (58699685).

The spelling of 18218404 in words is "eighteen million, two hundred eighteen thousand, four hundred four".