21253128383808 has 224 divisors, whose sum is σ = 63806272387200. Its totient is φ = 6934643269632.

The previous prime is 21253128383783. The next prime is 21253128383827. The reversal of 21253128383808 is 80838382135212.

21253128383808 is a `hidden beast` number, since 2 + 1 + 2 + 531 + 28 + 3 + 8 + 3 + 80 + 8 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39387903 + ... + 39923841.

It is an arithmetic number, because the mean of its divisors is an integer number (284849430300).

Almost surely, 2^{21253128383808} 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 21253128383808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31903136193600).

21253128383808 is an abundant number, since it is smaller than the sum of its proper divisors (42553144003392).

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

21253128383808 is a wasteful number, since it uses less digits than its factorization.

21253128383808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536446 (or 536430 counting only the distinct ones).

The product of its (nonzero) digits is 4423680, while the sum is 54.

The spelling of 21253128383808 in words is "twenty-one trillion, two hundred fifty-three billion, one hundred twenty-eight million, three hundred eighty-three thousand, eight hundred eight".