21712572 has 36 divisors (see below), whose sum is σ = 62725936. Its totient is φ = 6203520.

The previous prime is 21712567. The next prime is 21712631. The reversal of 21712572 is 27521712.

21712572 is a `hidden beast` number, since 21 + 71 + 2 + 572 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42829 + ... + 43332.

Almost surely, 2^21712572 is an apocalyptic number.

It is an amenable number.

21712572 is an abundant number, since it is smaller than the sum of its proper divisors (41013364).

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

21712572 is a wasteful number, since it uses less digits than its factorization.

21712572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86178 (or 86173 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 21712572 is about 4659.6750959697. The cubic root of 21712572 is about 278.9783002355.

The spelling of 21712572 in words is "twenty-one million, seven hundred twelve thousand, five hundred seventy-two".