20931112913 has 4 divisors (see below), whose sum is σ = 20933316720. Its totient is φ = 20928909108.

The previous prime is 20931112907. The next prime is 20931112949. The reversal of 20931112913 is 31921113902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20931112913 is a prime.

It is a super-2 number, since 2×20931112913² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20931112913.

It is not an unprimeable number, because it can be changed into a prime (20931112513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1087595 + ... + 1106672.

It is an arithmetic number, because the mean of its divisors is an integer number (5233329180).

Almost surely, 2^20931112913 is an apocalyptic number.

It is an amenable number.

20931112913 is a deficient number, since it is larger than the sum of its proper divisors (2203807).

20931112913 is an equidigital number, since it uses as much as digits as its factorization.

20931112913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2203806.

The product of its (nonzero) digits is 2916, while the sum is 32.

The spelling of 20931112913 in words is "twenty billion, nine hundred thirty-one million, one hundred twelve thousand, nine hundred thirteen".