21039604 has 24 divisors (see below), whose sum is σ = 37506560. Its totient is φ = 10325664.

The previous prime is 21039589. The next prime is 21039611. The reversal of 21039604 is 40693012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91762 + ... + 91990.

Almost surely, 2^21039604 is an apocalyptic number.

It is an amenable number.

21039604 is a deficient number, since it is larger than the sum of its proper divisors (16466956).

21039604 is a wasteful number, since it uses less digits than its factorization.

21039604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21039604 is about 4586.8948102175. The cubic root of 21039604 is about 276.0657443326.

The spelling of 21039604 in words is "twenty-one million, thirty-nine thousand, six hundred four".