21504684 has 24 divisors (see below), whose sum is σ = 50319360. Its totient is φ = 7147984.

The previous prime is 21504647. The next prime is 21504727. The reversal of 21504684 is 48640512.

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, 2257 + ... + 6935.

It is an arithmetic number, because the mean of its divisors is an integer number (2096640).

Almost surely, 2^21504684 is an apocalyptic number.

It is an amenable number.

21504684 is an abundant number, since it is smaller than the sum of its proper divisors (28814676).

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

21504684 is a wasteful number, since it uses less digits than its factorization.

21504684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5069 (or 5067 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 21504684 is about 4637.3143089508. The cubic root of 21504684 is about 278.0850799751.

The spelling of 21504684 in words is "twenty-one million, five hundred four thousand, six hundred eighty-four".