21937924 has 24 divisors (see below), whose sum is σ = 39050648. Its totient is φ = 10782720.

The previous prime is 21937921. The next prime is 21937931. The reversal of 21937924 is 42973912.

It can be written as a sum of positive squares in 4 ways, for example, as 777924 + 21160000 = 882^2 + 4600^2 .

It is not an unprimeable number, because it can be changed into a prime (21937921) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 113572 + ... + 113764.

Almost surely, 2^21937924 is an apocalyptic number.

It is an amenable number.

21937924 is a deficient number, since it is larger than the sum of its proper divisors (17112724).

21937924 is a wasteful number, since it uses less digits than its factorization.

21937924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535 (or 533 counting only the distinct ones).

The product of its digits is 27216, while the sum is 37.

The square root of 21937924 is about 4683.7937614716. The cubic root of 21937924 is about 279.9401402650.

The spelling of 21937924 in words is "twenty-one million, nine hundred thirty-seven thousand, nine hundred twenty-four".