21659248656 has 120 divisors (see below), whose sum is σ = 61993767264. Its totient is φ = 7057290240.

The previous prime is 21659248613. The next prime is 21659248669. The reversal of 21659248656 is 65684295612.

21659248656 is a `hidden beast` number, since 2 + 1 + 6 + 592 + 48 + 6 + 5 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1255320 + ... + 1272456.

Almost surely, 2^21659248656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21659248656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30996883632).

21659248656 is an abundant number, since it is smaller than the sum of its proper divisors (40334518608).

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

21659248656 is a wasteful number, since it uses less digits than its factorization.

21659248656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17349 (or 17340 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 54.

The spelling of 21659248656 in words is "twenty-one billion, six hundred fifty-nine million, two hundred forty-eight thousand, six hundred fifty-six".