21015112218 has 32 divisors (see below), whose sum is σ = 43910069760. Its totient is φ = 6696513600.

The previous prime is 21015112163. The next prime is 21015112219. The reversal of 21015112218 is 81221151012.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21015112219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 580330 + ... + 615477.

It is an arithmetic number, because the mean of its divisors is an integer number (1372189680).

Almost surely, 2^21015112218 is an apocalyptic number.

21015112218 is an abundant number, since it is smaller than the sum of its proper divisors (22894957542).

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

21015112218 is a wasteful number, since it uses less digits than its factorization.

21015112218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1195942.

The product of its (nonzero) digits is 320, while the sum is 24.

The spelling of 21015112218 in words is "twenty-one billion, fifteen million, one hundred twelve thousand, two hundred eighteen".