21937564 has 24 divisors (see below), whose sum is σ = 42392448. Its totient is φ = 9849840.

The previous prime is 21937549. The next prime is 21937577. The reversal of 21937564 is 46573912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 649 + ... + 6655.

It is an arithmetic number, because the mean of its divisors is an integer number (1766352).

Almost surely, 2^21937564 is an apocalyptic number.

It is an amenable number.

21937564 is a deficient number, since it is larger than the sum of its proper divisors (20454884).

21937564 is a wasteful number, since it uses less digits than its factorization.

21937564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6105 (or 6103 counting only the distinct ones).

The product of its digits is 45360, while the sum is 37.

The square root of 21937564 is about 4683.7553309284. The cubic root of 21937564 is about 279.9386089898.

The spelling of 21937564 in words is "twenty-one million, nine hundred thirty-seven thousand, five hundred sixty-four".