21938288 has 20 divisors (see below), whose sum is σ = 42690720. Its totient is φ = 10921344.

The previous prime is 21938269. The next prime is 21938327. The reversal of 21938288 is 88283912.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 956 + ... + 6692.

It is an arithmetic number, because the mean of its divisors is an integer number (2134536).

Almost surely, 2^21938288 is an apocalyptic number.

It is an amenable number.

21938288 is a deficient number, since it is larger than the sum of its proper divisors (20752432).

21938288 is a wasteful number, since it uses less digits than its factorization.

21938288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5984 (or 5978 counting only the distinct ones).

The product of its digits is 55296, while the sum is 41.

The square root of 21938288 is about 4683.8326187002. The cubic root of 21938288 is about 279.9416885374.

The spelling of 21938288 in words is "twenty-one million, nine hundred thirty-eight thousand, two hundred eighty-eight".