21975688800 has 720 divisors, whose sum is σ = 90914337360. Its totient is φ = 5120962560.

The previous prime is 21975688799. The next prime is 21975688807. The reversal of 21975688800 is 888657912.

It is a tau number, because it is divible by the number of its divisors (720).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21975688807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 16004914 + ... + 16006286.

It is an arithmetic number, because the mean of its divisors is an integer number (126269913).

Almost surely, 2^21975688800 is an apocalyptic number.

21975688800 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 21975688800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45457168680).

21975688800 is an abundant number, since it is smaller than the sum of its proper divisors (68938648560).

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

21975688800 is a wasteful number, since it uses less digits than its factorization.

21975688800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1437 (or 1415 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 54.

The spelling of 21975688800 in words is "twenty-one billion, nine hundred seventy-five million, six hundred eighty-eight thousand, eight hundred".