21556032242688 has 792 divisors, whose sum is σ = 67155695871264. Its totient is φ = 6901803417600.

The previous prime is 21556032242663. The next prime is 21556032242699. The reversal of 21556032242688 is 88624223065512.

21556032242688 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 603 + 2 + 2 + 4 + 26 + 8 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 164549864383 + ... + 164549864513.

It is an arithmetic number, because the mean of its divisors is an integer number (84792545292).

Almost surely, 2^{21556032242688} 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 21556032242688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33577847935632).

21556032242688 is an abundant number, since it is smaller than the sum of its proper divisors (45599663628576).

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

21556032242688 is an equidigital number, since it uses as much as digits as its factorization.

21556032242688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461 (or 304 counting only the distinct ones).

The product of its (nonzero) digits is 11059200, while the sum is 54.

The spelling of 21556032242688 in words is "twenty-one trillion, five hundred fifty-six billion, thirty-two million, two hundred forty-two thousand, six hundred eighty-eight".