21605760000 has 990 divisors, whose sum is σ = 88453260896. Its totient is φ = 5068800000.

The previous prime is 21605759993. The next prime is 21605760019. The reversal of 21605760000 is 6750612.

21605760000 is a `hidden beast` number, since 2 + 1 + 6 + 0 + 57 + 600 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (990).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 696959985 + ... + 696960015.

Almost surely, 2^21605760000 is an apocalyptic number.

21605760000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21605760000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44226630448).

21605760000 is an abundant number, since it is smaller than the sum of its proper divisors (66847500896).

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

21605760000 is a wasteful number, since it uses less digits than its factorization.

21605760000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The spelling of 21605760000 in words is "twenty-one billion, six hundred five million, seven hundred sixty thousand".