21956977516 has 6 divisors (see below), whose sum is σ = 38424710660. Its totient is φ = 10978488756.

The previous prime is 21956977501. The next prime is 21956977529. The reversal of 21956977516 is 61577965912.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2744622186 + ... + 2744622193.

Almost surely, 2^21956977516 is an apocalyptic number.

It is an amenable number.

21956977516 is a deficient number, since it is larger than the sum of its proper divisors (16467733144).

21956977516 is a wasteful number, since it uses less digits than its factorization.

21956977516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5489244383 (or 5489244381 counting only the distinct ones).

The product of its digits is 7144200, while the sum is 58.

The spelling of 21956977516 in words is "twenty-one billion, nine hundred fifty-six million, nine hundred seventy-seven thousand, five hundred sixteen".