12766221361 has 4 divisors (see below), whose sum is σ = 12774464500. Its totient is φ = 12757978224.

The previous prime is 12766221329. The next prime is 12766221371. The reversal of 12766221361 is 16312266721.

12766221361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16312266721 = 16703 ⋅976607.

It can be written as a sum of positive squares in 2 ways, for example, as 2176782336 + 10589439025 = 46656^2 + 102905^2 .

It is a cyclic number.

It is not a de Polignac number, because 12766221361 - 2⁵ = 12766221329 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12766221361.

It is not an unprimeable number, because it can be changed into a prime (12766221371) 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 3 ways as a sum of consecutive naturals, for example, 4119246 + ... + 4122343.

It is an arithmetic number, because the mean of its divisors is an integer number (3193616125).

Almost surely, 2^12766221361 is an apocalyptic number.

It is an amenable number.

12766221361 is a deficient number, since it is larger than the sum of its proper divisors (8243139).

12766221361 is an equidigital number, since it uses as much as digits as its factorization.

12766221361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8243138.

The product of its digits is 36288, while the sum is 37.

The spelling of 12766221361 in words is "twelve billion, seven hundred sixty-six million, two hundred twenty-one thousand, three hundred sixty-one".