21804324 has 24 divisors (see below), whose sum is σ = 53555040. Its totient is φ = 6885504.

The previous prime is 21804283. The next prime is 21804329. The reversal of 21804324 is 42340812.

It is a junction number, because it is equal to n+sod(n) for n = 21804294 and 21804303.

It is not an unprimeable number, because it can be changed into a prime (21804329) by changing a digit.

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, 47589 + ... + 48044.

It is an arithmetic number, because the mean of its divisors is an integer number (2231460).

Almost surely, 2^21804324 is an apocalyptic number.

It is an amenable number.

21804324 is an abundant number, since it is smaller than the sum of its proper divisors (31750716).

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

21804324 is a wasteful number, since it uses less digits than its factorization.

21804324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95659 (or 95657 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 21804324 is about 4669.5100385372. The cubic root of 21804324 is about 279.3707126148.

The spelling of 21804324 in words is "twenty-one million, eight hundred four thousand, three hundred twenty-four".