21560820253875 has 72 divisors (see below), whose sum is σ = 45212600171232. Its totient is φ = 9856374948000.

The previous prime is 21560820253733. The next prime is 21560820253997. The reversal of 21560820253875 is 57835202806512.

It is a happy number.

21560820253875 is a `hidden beast` number, since 2 + 1 + 5 + 608 + 2 + 0 + 25 + 3 + 8 + 7 + 5 = 666.

It is not a de Polignac number, because 21560820253875 - 2⁹ = 21560820253363 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 195507871 + ... + 195618120.

It is an arithmetic number, because the mean of its divisors is an integer number (627952780156).

Almost surely, 2^{21560820253875} is an apocalyptic number.

21560820253875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21560820253875 is an abundant number, since it is smaller than the sum of its proper divisors (23651779917357).

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

21560820253875 is a wasteful number, since it uses less digits than its factorization.

21560820253875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391126026 (or 391126006 counting only the distinct ones).

The product of its (nonzero) digits is 8064000, while the sum is 54.

The spelling of 21560820253875 in words is "twenty-one trillion, five hundred sixty billion, eight hundred twenty million, two hundred fifty-three thousand, eight hundred seventy-five".