21255182208 has 384 divisors, whose sum is σ = 68567990400. Its totient is φ = 6277201920.

The previous prime is 21255182197. The next prime is 21255182213. The reversal of 21255182208 is 80228155212.

21255182208 is a `hidden beast` number, since 2 + 1 + 2 + 551 + 82 + 20 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 49315753 + ... + 49316183.

It is an arithmetic number, because the mean of its divisors is an integer number (178562475).

Almost surely, 2^21255182208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21255182208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34283995200).

21255182208 is an abundant number, since it is smaller than the sum of its proper divisors (47312808192).

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

21255182208 is a wasteful number, since it uses less digits than its factorization.

21255182208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590 (or 575 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 36.

The spelling of 21255182208 in words is "twenty-one billion, two hundred fifty-five million, one hundred eighty-two thousand, two hundred eight".