21905224 has 32 divisors (see below), whose sum is σ = 45043200. Its totient is φ = 9904320.

The previous prime is 21905209. The next prime is 21905227. The reversal of 21905224 is 42250912.

It is not an unprimeable number, because it can be changed into a prime (21905227) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 19609 + ... + 20695.

It is an arithmetic number, because the mean of its divisors is an integer number (1407600).

Almost surely, 2^21905224 is an apocalyptic number.

It is an amenable number.

21905224 is an abundant number, since it is smaller than the sum of its proper divisors (23137976).

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

21905224 is a wasteful number, since it uses less digits than its factorization.

21905224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1333 (or 1329 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21905224 is about 4680.3016996771. The cubic root of 21905224 is about 279.8009810234.

The spelling of 21905224 in words is "twenty-one million, nine hundred five thousand, two hundred twenty-four".