12111972721 has 2 divisors, whose sum is σ = 12111972722. Its totient is φ = 12111972720.

The previous prime is 12111972701. The next prime is 12111972797. The reversal of 12111972721 is 12727911121.

12111972721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11742756496 + 369216225 = 108364^2 + 19215^2 .

It is a cyclic number.

It is not a de Polignac number, because 12111972721 - 2²⁷ = 11977754993 is a prime.

It is not a weakly prime, because it can be changed into another prime (12111972701) 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 as a sum of consecutive naturals, namely, 6055986360 + 6055986361.

It is an arithmetic number, because the mean of its divisors is an integer number (6055986361).

Almost surely, 2^12111972721 is an apocalyptic number.

It is an amenable number.

12111972721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12111972721 is an equidigital number, since it uses as much as digits as its factorization.

12111972721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 34.

The spelling of 12111972721 in words is "twelve billion, one hundred eleven million, nine hundred seventy-two thousand, seven hundred twenty-one".