21856622684832 has 576 divisors, whose sum is σ = 69540379324416. Its totient is φ = 6466393866240.

The previous prime is 21856622684761. The next prime is 21856622684893. The reversal of 21856622684832 is 23848622665812.

It is a happy number.

21856622684832 is a `hidden beast` number, since 2 + 1 + 8 + 566 + 2 + 2 + 68 + 4 + 8 + 3 + 2 = 666.

It is a super-2 number, since 2×21856622684832² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21856622684832.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13807088713 + ... + 13807090295.

It is an arithmetic number, because the mean of its divisors is an integer number (120729825216).

Almost surely, 2^{21856622684832} 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 21856622684832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34770189662208).

21856622684832 is an abundant number, since it is smaller than the sum of its proper divisors (47683756639584).

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

21856622684832 is a wasteful number, since it uses less digits than its factorization.

21856622684832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2333 (or 2322 counting only the distinct ones).

The product of its digits is 106168320, while the sum is 63.

The spelling of 21856622684832 in words is "twenty-one trillion, eight hundred fifty-six billion, six hundred twenty-two million, six hundred eighty-four thousand, eight hundred thirty-two".