21734621856 has 216 divisors, whose sum is σ = 66008202624. Its totient is φ = 6782330880.

The previous prime is 21734621837. The next prime is 21734621893. The reversal of 21734621856 is 65812643712.

21734621856 is a `hidden beast` number, since 2 + 1 + 7 + 3 + 462 + 185 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 18560151 + ... + 18561321.

Almost surely, 2^21734621856 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 21734621856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33004101312).

21734621856 is an abundant number, since it is smaller than the sum of its proper divisors (44273580768).

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

21734621856 is a wasteful number, since it uses less digits than its factorization.

21734621856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1444 (or 1416 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 21734621856 in words is "twenty-one billion, seven hundred thirty-four million, six hundred twenty-one thousand, eight hundred fifty-six".