21810604 has 6 divisors (see below), whose sum is σ = 38168564. Its totient is φ = 10905300.

The previous prime is 21810587. The next prime is 21810617. The reversal of 21810604 is 40601812.

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 as a sum of consecutive naturals, namely, 2726322 + ... + 2726329.

Almost surely, 2^21810604 is an apocalyptic number.

It is an amenable number.

21810604 is a deficient number, since it is larger than the sum of its proper divisors (16357960).

21810604 is a wasteful number, since it uses less digits than its factorization.

21810604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5452655 (or 5452653 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 21810604 is about 4670.1824375500. The cubic root of 21810604 is about 279.3975311435.

The spelling of 21810604 in words is "twenty-one million, eight hundred ten thousand, six hundred four".