12391979091 has 16 divisors (see below), whose sum is σ = 17098211328. Its totient is φ = 7974864000.

The previous prime is 12391979069. The next prime is 12391979111. The reversal of 12391979091 is 19097919321.

12391979091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12391979091 - 2¹⁷ = 12391848019 is a prime.

It is a super-2 number, since 2×12391979091² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12391979291) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 128851 + ... + 203436.

It is an arithmetic number, because the mean of its divisors is an integer number (1068638208).

Almost surely, 2^12391979091 is an apocalyptic number.

12391979091 is a deficient number, since it is larger than the sum of its proper divisors (4706232237).

12391979091 is a wasteful number, since it uses less digits than its factorization.

12391979091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332722.

The product of its (nonzero) digits is 275562, while the sum is 51.

The spelling of 12391979091 in words is "twelve billion, three hundred ninety-one million, nine hundred seventy-nine thousand, ninety-one".