21839568 has 20 divisors (see below), whose sum is σ = 56419008. Its totient is φ = 7279840.

The previous prime is 21839563. The next prime is 21839591. The reversal of 21839568 is 86593812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21839561) 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 3 ways as a sum of consecutive naturals, for example, 227448 + ... + 227543.

Almost surely, 2^21839568 is an apocalyptic number.

It is an amenable number.

21839568 is an abundant number, since it is smaller than the sum of its proper divisors (34579440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21839568 is a wasteful number, since it uses less digits than its factorization.

21839568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455002 (or 454996 counting only the distinct ones).

The product of its digits is 103680, while the sum is 42.

The square root of 21839568 is about 4673.2823582574. The cubic root of 21839568 is about 279.5211543518.

The spelling of 21839568 in words is "twenty-one million, eight hundred thirty-nine thousand, five hundred sixty-eight".