21988264 has 16 divisors (see below), whose sum is σ = 42650100. Its totient is φ = 10614912.

The previous prime is 21988247. The next prime is 21988279. The reversal of 21988264 is 46288912.

It can be written as a sum of positive squares in 2 ways, for example, as 21252100 + 736164 = 4610^2 + 858^2 .

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, 47157 + ... + 47620.

Almost surely, 2^21988264 is an apocalyptic number.

It is an amenable number.

21988264 is a deficient number, since it is larger than the sum of its proper divisors (20661836).

21988264 is a wasteful number, since it uses less digits than its factorization.

21988264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94812 (or 94808 counting only the distinct ones).

The product of its digits is 55296, while the sum is 40.

The square root of 21988264 is about 4689.1645311292. The cubic root of 21988264 is about 280.1540988491.

The spelling of 21988264 in words is "twenty-one million, nine hundred eighty-eight thousand, two hundred sixty-four".