21939986668 has 12 divisors (see below), whose sum is σ = 38399721472. Its totient is φ = 10968637680.

The previous prime is 21939986657. The next prime is 21939986711. The reversal of 21939986668 is 86668993912.

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, 302055 + ... + 367582.

Almost surely, 2^21939986668 is an apocalyptic number.

It is an amenable number.

21939986668 is a deficient number, since it is larger than the sum of its proper divisors (16459734804).

21939986668 is a wasteful number, since it uses less digits than its factorization.

21939986668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677832 (or 677830 counting only the distinct ones).

The product of its digits is 60466176, while the sum is 67.

The spelling of 21939986668 in words is "twenty-one billion, nine hundred thirty-nine million, nine hundred eighty-six thousand, six hundred sixty-eight".