21916568 has 32 divisors (see below), whose sum is σ = 42288960. Its totient is φ = 10644480.

The previous prime is 21916561. The next prime is 21916577. The reversal of 21916568 is 86561912.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21916561) 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, 47105 + ... + 47567.

It is an arithmetic number, because the mean of its divisors is an integer number (1321530).

Almost surely, 2^21916568 is an apocalyptic number.

It is an amenable number.

21916568 is a deficient number, since it is larger than the sum of its proper divisors (20372392).

21916568 is a wasteful number, since it uses less digits than its factorization.

21916568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627 (or 623 counting only the distinct ones).

The product of its digits is 25920, while the sum is 38.

The square root of 21916568 is about 4681.5134305051. The cubic root of 21916568 is about 279.8492726177.

The spelling of 21916568 in words is "twenty-one million, nine hundred sixteen thousand, five hundred sixty-eight".