21112518165 has 8 divisors (see below), whose sum is σ = 33780029088. Its totient is φ = 11260009680.

The previous prime is 21112518157. The next prime is 21112518221. The reversal of 21112518165 is 56181521112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21112518165 - 2³ = 21112518157 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 703750591 + ... + 703750620.

It is an arithmetic number, because the mean of its divisors is an integer number (4222503636).

Almost surely, 2^21112518165 is an apocalyptic number.

It is an amenable number.

21112518165 is a deficient number, since it is larger than the sum of its proper divisors (12667510923).

21112518165 is a wasteful number, since it uses less digits than its factorization.

21112518165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1407501219.

The product of its digits is 4800, while the sum is 33.

The spelling of 21112518165 in words is "twenty-one billion, one hundred twelve million, five hundred eighteen thousand, one hundred sixty-five".