21899604 has 24 divisors (see below), whose sum is σ = 54105408. Its totient is φ = 6870400.

The previous prime is 21899543. The next prime is 21899627. The reversal of 21899604 is 40699812.

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 7 ways as a sum of consecutive naturals, for example, 53472 + ... + 53879.

It is an arithmetic number, because the mean of its divisors is an integer number (2254392).

Almost surely, 2^21899604 is an apocalyptic number.

It is an amenable number.

21899604 is an abundant number, since it is smaller than the sum of its proper divisors (32205804).

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

21899604 is a wasteful number, since it uses less digits than its factorization.

21899604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107375 (or 107373 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 21899604 is about 4679.7012725173. The cubic root of 21899604 is about 279.7770504150. Note that the first 3 decimals are identical.

The spelling of 21899604 in words is "twenty-one million, eight hundred ninety-nine thousand, six hundred four".