21955372 has 6 divisors (see below), whose sum is σ = 38421908. Its totient is φ = 10977684.

The previous prime is 21955343. The next prime is 21955399. The reversal of 21955372 is 27355912.

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 as a sum of consecutive naturals, namely, 2744418 + ... + 2744425.

Almost surely, 2^21955372 is an apocalyptic number.

It is an amenable number.

21955372 is a deficient number, since it is larger than the sum of its proper divisors (16466536).

21955372 is a wasteful number, since it uses less digits than its factorization.

21955372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5488847 (or 5488845 counting only the distinct ones).

The product of its digits is 18900, while the sum is 34.

The square root of 21955372 is about 4685.6559839578. The cubic root of 21955372 is about 280.0143360007.

The spelling of 21955372 in words is "twenty-one million, nine hundred fifty-five thousand, three hundred seventy-two".