21669256828800 has 1728 divisors, whose sum is σ = 98311043226240. Its totient is φ = 4511091916800.

The previous prime is 21669256828753. The next prime is 21669256828801. The reversal of 21669256828800 is 882865296612.

21669256828800 is a `hidden beast` number, since 2 + 1 + 6 + 69 + 2 + 568 + 2 + 8 + 8 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21669256828801) by changing a digit.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 743687832 + ... + 743716968.

It is an arithmetic number, because the mean of its divisors is an integer number (56892964830).

Almost surely, 2^{21669256828800} is an apocalyptic number.

21669256828800 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 21669256828800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49155521613120).

21669256828800 is an abundant number, since it is smaller than the sum of its proper divisors (76641786397440).

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

21669256828800 is a wasteful number, since it uses less digits than its factorization.

21669256828800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29229 (or 29202 counting only the distinct ones).

The product of its (nonzero) digits is 39813120, while the sum is 63.

The spelling of 21669256828800 in words is "twenty-one trillion, six hundred sixty-nine billion, two hundred fifty-six million, eight hundred twenty-eight thousand, eight hundred".