21977561016 has 48 divisors (see below), whose sum is σ = 59552321400. Its totient is φ = 7322190912.

The previous prime is 21977560987. The next prime is 21977561071. The reversal of 21977561016 is 61016577912.

21977561016 is a `hidden beast` number, since 2 + 1 + 9 + 77 + 561 + 0 + 16 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70650 + ... + 221238.

Almost surely, 2^21977561016 is an apocalyptic number.

It is an amenable number.

21977561016 is an abundant number, since it is smaller than the sum of its proper divisors (37574760384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21977561016 is a wasteful number, since it uses less digits than its factorization.

21977561016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152628 (or 152621 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 45.

The spelling of 21977561016 in words is "twenty-one billion, nine hundred seventy-seven million, five hundred sixty-one thousand, sixteen".