21930868 has 24 divisors (see below), whose sum is σ = 40384512. Its totient is φ = 10400544.

The previous prime is 21930851. The next prime is 21930869. The reversal of 21930868 is 86803912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21930869) 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, 10746 + ... + 12622.

It is an arithmetic number, because the mean of its divisors is an integer number (1682688).

Almost surely, 2^21930868 is an apocalyptic number.

It is an amenable number.

21930868 is a deficient number, since it is larger than the sum of its proper divisors (18453644).

21930868 is a wasteful number, since it uses less digits than its factorization.

21930868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2031 (or 2029 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 21930868 is about 4683.0404653387. The cubic root of 21930868 is about 279.9101242155.

The spelling of 21930868 in words is "twenty-one million, nine hundred thirty thousand, eight hundred sixty-eight".