21707372 has 6 divisors (see below), whose sum is σ = 37987908. Its totient is φ = 10853684.

The previous prime is 21707359. The next prime is 21707393. The reversal of 21707372 is 27370712.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2713418 + ... + 2713425.

It is an arithmetic number, because the mean of its divisors is an integer number (6331318).

Almost surely, 2^21707372 is an apocalyptic number.

It is an amenable number.

21707372 is a deficient number, since it is larger than the sum of its proper divisors (16280536).

21707372 is a wasteful number, since it uses less digits than its factorization.

21707372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5426847 (or 5426845 counting only the distinct ones).

The product of its (nonzero) digits is 4116, while the sum is 29.

The square root of 21707372 is about 4659.1170837402. The cubic root of 21707372 is about 278.9560273792.

The spelling of 21707372 in words is "twenty-one million, seven hundred seven thousand, three hundred seventy-two".