216979722864 has 80 divisors (see below), whose sum is σ = 625110704640. Its totient is φ = 72059647680.

The previous prime is 216979722859. The next prime is 216979722871. The reversal of 216979722864 is 468227979612.

216979722864 is a `hidden beast` number, since 216 + 9 + 79 + 72 + 286 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 809622 + ... + 1043765.

It is an arithmetic number, because the mean of its divisors is an integer number (7813883808).

Almost surely, 2^216979722864 is an apocalyptic number.

216979722864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

216979722864 is an abundant number, since it is smaller than the sum of its proper divisors (408130981776).

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

216979722864 is a wasteful number, since it uses less digits than its factorization.

216979722864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1853675 (or 1853663 counting only the distinct ones).

The product of its digits is 36578304, while the sum is 63.

The spelling of 216979722864 in words is "two hundred sixteen billion, nine hundred seventy-nine million, seven hundred twenty-two thousand, eight hundred sixty-four".