21100225686624 has 576 divisors, whose sum is σ = 75978862202880. Its totient is φ = 5415738900480.

The previous prime is 21100225686623. The next prime is 21100225686647. The reversal of 21100225686624 is 42668652200112.

21100225686624 is a `hidden beast` number, since 2 + 1 + 1 + 0 + 0 + 2 + 2 + 568 + 66 + 24 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21100225686624.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100225686623) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 77421507 + ... + 77693565.

It is an arithmetic number, because the mean of its divisors is an integer number (131907746880).

Almost surely, 2^{21100225686624} is an apocalyptic number.

21100225686624 is a gapful number since it is divisible by the number (24) 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 21100225686624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37989431101440).

21100225686624 is an abundant number, since it is smaller than the sum of its proper divisors (54878636516256).

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

21100225686624 is a wasteful number, since it uses less digits than its factorization.

21100225686624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272203 (or 272192 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

Adding to 21100225686624 its reverse (42668652200112), we get a palindrome (63768877886736).

The spelling of 21100225686624 in words is "twenty-one trillion, one hundred billion, two hundred twenty-five million, six hundred eighty-six thousand, six hundred twenty-four".