21568280832 has 360 divisors, whose sum is σ = 74098270400. Its totient is φ = 6112309248.

The previous prime is 21568280819. The next prime is 21568280893. The reversal of 21568280832 is 23808286512.

21568280832 is a `hidden beast` number, since 2 + 1 + 568 + 2 + 8 + 0 + 83 + 2 = 666.

It is a super-2 number, since 2×21568280832² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 20175594 + ... + 20176662.

Almost surely, 2^21568280832 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 21568280832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37049135200).

21568280832 is an abundant number, since it is smaller than the sum of its proper divisors (52529989568).

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

21568280832 is a wasteful number, since it uses less digits than its factorization.

21568280832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1243 (or 1220 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 21568280832 in words is "twenty-one billion, five hundred sixty-eight million, two hundred eighty thousand, eight hundred thirty-two".