21757604317056 has 320 divisors, whose sum is σ = 67087735228800. Its totient is φ = 6992462868480.

The previous prime is 21757604317051. The next prime is 21757604317121. The reversal of 21757604317056 is 65071340675712.

21757604317056 is a `hidden beast` number, since 2 + 1 + 7 + 576 + 0 + 4 + 3 + 17 + 0 + 56 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21757604316993 and 21757604317011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21757604317051) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 86332926 + ... + 86584578.

It is an arithmetic number, because the mean of its divisors is an integer number (209649172590).

Almost surely, 2^{21757604317056} 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 21757604317056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33543867614400).

21757604317056 is an abundant number, since it is smaller than the sum of its proper divisors (45330130911744).

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

21757604317056 is a wasteful number, since it uses less digits than its factorization.

21757604317056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251979 (or 251958 counting only the distinct ones).

The product of its (nonzero) digits is 7408800, while the sum is 54.

The spelling of 21757604317056 in words is "twenty-one trillion, seven hundred fifty-seven billion, six hundred four million, three hundred seventeen thousand, fifty-six".