21945650756688 has 360 divisors, whose sum is σ = 66130905297600. Its totient is φ = 6774925667328.

The previous prime is 21945650756677. The next prime is 21945650756713. The reversal of 21945650756688 is 88665705654912.

21945650756688 is a `hidden beast` number, since 2 + 1 + 9 + 4 + 5 + 6 + 50 + 7 + 566 + 8 + 8 = 666.

It is a super-2 number, since 2×21945650756688² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

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, 7391595268 + ... + 7391598236.

It is an arithmetic number, because the mean of its divisors is an integer number (183696959160).

Almost surely, 2^{21945650756688} 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 21945650756688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33065452648800).

21945650756688 is an abundant number, since it is smaller than the sum of its proper divisors (44185254540912).

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

21945650756688 is a wasteful number, since it uses less digits than its factorization.

21945650756688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4319 (or 4263 counting only the distinct ones).

The product of its (nonzero) digits is 870912000, while the sum is 72.

The spelling of 21945650756688 in words is "twenty-one trillion, nine hundred forty-five billion, six hundred fifty million, seven hundred fifty-six thousand, six hundred eighty-eight".