21604568 has 16 divisors (see below), whose sum is σ = 40997880. Its totient is φ = 10671808.

The previous prime is 21604529. The next prime is 21604579. The reversal of 21604568 is 86540612.

It is a congruent number.

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, 15605 + ... + 16932.

Almost surely, 2^21604568 is an apocalyptic number.

It is an amenable number.

21604568 is a deficient number, since it is larger than the sum of its proper divisors (19393312).

21604568 is a wasteful number, since it uses less digits than its factorization.

21604568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32626 (or 32622 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 21604568 is about 4648.0714280226. The cubic root of 21604568 is about 278.5149608346.

The spelling of 21604568 in words is "twenty-one million, six hundred four thousand, five hundred sixty-eight".