12979509991 has 16 divisors (see below), whose sum is σ = 15221088000. Its totient is φ = 11063089464.

The previous prime is 12979509953. The next prime is 12979509997. The reversal of 12979509991 is 19990597921.

It is not a de Polignac number, because 12979509991 - 2⁹ = 12979509479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12979509997) 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, 44305 + ... + 167098.

It is an arithmetic number, because the mean of its divisors is an integer number (951318000).

Almost surely, 2^12979509991 is an apocalyptic number.

12979509991 is a deficient number, since it is larger than the sum of its proper divisors (2241578009).

12979509991 is an equidigital number, since it uses as much as digits as its factorization.

12979509991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211603 (or 211589 counting only the distinct ones).

The product of its (nonzero) digits is 4133430, while the sum is 61.

The spelling of 12979509991 in words is "twelve billion, nine hundred seventy-nine million, five hundred nine thousand, nine hundred ninety-one".