21253086838368 has 960 divisors, whose sum is σ = 81198195724800. Its totient is φ = 5291382620160.

The previous prime is 21253086838351. The next prime is 21253086838441. The reversal of 21253086838368 is 86383868035212.

21253086838368 is a `hidden beast` number, since 2 + 1 + 2 + 530 + 8 + 6 + 8 + 38 + 3 + 68 = 666.

It is a super-2 number, since 2×21253086838368² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 804509896 + ... + 804536312.

It is an arithmetic number, because the mean of its divisors is an integer number (84581453880).

Almost surely, 2^{21253086838368} is an apocalyptic number.

21253086838368 is a gapful number since it is divisible by the number (28) 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 21253086838368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40599097862400).

21253086838368 is an abundant number, since it is smaller than the sum of its proper divisors (59945108886432).

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

21253086838368 is a wasteful number, since it uses less digits than its factorization.

21253086838368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26625 (or 26608 counting only the distinct ones).

The product of its (nonzero) digits is 79626240, while the sum is 63.

The spelling of 21253086838368 in words is "twenty-one trillion, two hundred fifty-three billion, eighty-six million, eight hundred thirty-eight thousand, three hundred sixty-eight".