21804936 has 16 divisors (see below), whose sum is σ = 54512400. Its totient is φ = 7268304.

The previous prime is 21804919. The next prime is 21804941. The reversal of 21804936 is 63940812.

It is a junction number, because it is equal to n+sod(n) for n = 21804897 and 21804906.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454246 + ... + 454293.

It is an arithmetic number, because the mean of its divisors is an integer number (3407025).

Almost surely, 2^21804936 is an apocalyptic number.

It is an amenable number.

21804936 is an abundant number, since it is smaller than the sum of its proper divisors (32707464).

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

21804936 is a wasteful number, since it uses less digits than its factorization.

21804936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 908548 (or 908544 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21804936 is about 4669.5755695780. The cubic root of 21804936 is about 279.3733263667.

The spelling of 21804936 in words is "twenty-one million, eight hundred four thousand, nine hundred thirty-six".