21660692888 has 16 divisors (see below), whose sum is σ = 42379616880. Its totient is φ = 10359461728.

The previous prime is 21660692863. The next prime is 21660692891. The reversal of 21660692888 is 88829606612.

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, 58860395 + ... + 58860762.

It is an arithmetic number, because the mean of its divisors is an integer number (2648726055).

Almost surely, 2^21660692888 is an apocalyptic number.

It is an amenable number.

21660692888 is a deficient number, since it is larger than the sum of its proper divisors (20718923992).

21660692888 is a wasteful number, since it uses less digits than its factorization.

21660692888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117721186 (or 117721182 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 56.

The spelling of 21660692888 in words is "twenty-one billion, six hundred sixty million, six hundred ninety-two thousand, eight hundred eighty-eight".