21903204 has 24 divisors (see below), whose sum is σ = 52073280. Its totient is φ = 7163104.

The previous prime is 21903197. The next prime is 21903229. The reversal of 21903204 is 40230912.

It is a congruent number.

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, 16584 + ... + 17855.

It is an arithmetic number, because the mean of its divisors is an integer number (2169720).

Almost surely, 2^21903204 is an apocalyptic number.

It is an amenable number.

21903204 is an abundant number, since it is smaller than the sum of its proper divisors (30170076).

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

21903204 is a wasteful number, since it uses less digits than its factorization.

21903204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34499 (or 34497 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21903204 is about 4680.0858966476. The cubic root of 21903204 is about 279.7923801016.

The spelling of 21903204 in words is "twenty-one million, nine hundred three thousand, two hundred four".