21662572 has 12 divisors (see below), whose sum is σ = 38137680. Its totient is φ = 10766096.

The previous prime is 21662569. The next prime is 21662579. The reversal of 21662572 is 27526612.

It is not an unprimeable number, because it can be changed into a prime (21662579) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15547 + ... + 16882.

It is an arithmetic number, because the mean of its divisors is an integer number (3178140).

Almost surely, 2^21662572 is an apocalyptic number.

It is an amenable number.

21662572 is a deficient number, since it is larger than the sum of its proper divisors (16475108).

21662572 is a wasteful number, since it uses less digits than its factorization.

21662572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32600 (or 32598 counting only the distinct ones).

The product of its digits is 10080, while the sum is 31.

The square root of 21662572 is about 4654.3068227181. The cubic root of 21662572 is about 278.7639906643.

The spelling of 21662572 in words is "twenty-one million, six hundred sixty-two thousand, five hundred seventy-two".