21885385185 has 24 divisors (see below), whose sum is σ = 37939096104. Its totient is φ = 11670842880.

The previous prime is 21885385141. The next prime is 21885385213. The reversal of 21885385185 is 58158358812.

21885385185 is a `hidden beast` number, since 2 + 1 + 8 + 85 + 385 + 185 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1920542976 + 19964842209 = 43824^2 + 141297^2 .

It is not a de Polignac number, because 21885385185 - 2¹⁰ = 21885384161 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 23 ways as a sum of consecutive naturals, for example, 449955 + ... + 496215.

It is an arithmetic number, because the mean of its divisors is an integer number (1580795671).

Almost surely, 2^21885385185 is an apocalyptic number.

It is an amenable number.

21885385185 is a deficient number, since it is larger than the sum of its proper divisors (16053710919).

21885385185 is a wasteful number, since it uses less digits than its factorization.

21885385185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56785 (or 56782 counting only the distinct ones).

The product of its digits is 3072000, while the sum is 54.

The spelling of 21885385185 in words is "twenty-one billion, eight hundred eighty-five million, three hundred eighty-five thousand, one hundred eighty-five".