21660592800 has 1152 divisors, whose sum is σ = 95993856000. Its totient is φ = 4105728000.

The previous prime is 21660592771. The next prime is 21660592859. The reversal of 21660592800 is 829506612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 108847101 + ... + 108847299.

It is an arithmetic number, because the mean of its divisors is an integer number (83328000).

Almost surely, 2^21660592800 is an apocalyptic number.

21660592800 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 21660592800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47996928000).

21660592800 is an abundant number, since it is smaller than the sum of its proper divisors (74333263200).

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

21660592800 is a wasteful number, since it uses less digits than its factorization.

21660592800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 21660592800 in words is "twenty-one billion, six hundred sixty million, five hundred ninety-two thousand, eight hundred".