21902604 has 12 divisors (see below), whose sum is σ = 51106104. Its totient is φ = 7300864.

The previous prime is 21902597. The next prime is 21902623. The reversal of 21902604 is 40620912.

It is a tau number, because it is divible by the number of its divisors (12).

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 3 ways as a sum of consecutive naturals, for example, 912597 + ... + 912620.

It is an arithmetic number, because the mean of its divisors is an integer number (4258842).

Almost surely, 2^21902604 is an apocalyptic number.

It is an amenable number.

21902604 is an abundant number, since it is smaller than the sum of its proper divisors (29203500).

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

21902604 is a wasteful number, since it uses less digits than its factorization.

21902604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1825224 (or 1825222 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 21902604 is about 4680.0217948210. The cubic root of 21902604 is about 279.7898252705.

The spelling of 21902604 in words is "twenty-one million, nine hundred two thousand, six hundred four".