21881935864 has 16 divisors (see below), whose sum is σ = 42137512200. Its totient is φ = 10645265952.

The previous prime is 21881935843. The next prime is 21881935939. The reversal of 21881935864 is 46853918812.

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, 36962434 + ... + 36963025.

Almost surely, 2^21881935864 is an apocalyptic number.

It is an amenable number.

21881935864 is a deficient number, since it is larger than the sum of its proper divisors (20255576336).

21881935864 is a wasteful number, since it uses less digits than its factorization.

21881935864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73925502 (or 73925498 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 55.

The spelling of 21881935864 in words is "twenty-one billion, eight hundred eighty-one million, nine hundred thirty-five thousand, eight hundred sixty-four".