12666206305 has 4 divisors (see below), whose sum is σ = 15199447572. Its totient is φ = 10132965040.

The previous prime is 12666206299. The next prime is 12666206323. The reversal of 12666206305 is 50360266621.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7070119056 + 5596087249 = 84084^2 + 74807^2 .

It is not a de Polignac number, because 12666206305 - 2⁷ = 12666206177 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1266620626 + ... + 1266620635.

It is an arithmetic number, because the mean of its divisors is an integer number (3799861893).

Almost surely, 2^12666206305 is an apocalyptic number.

It is an amenable number.

12666206305 is a deficient number, since it is larger than the sum of its proper divisors (2533241267).

12666206305 is an equidigital number, since it uses as much as digits as its factorization.

12666206305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2533241266.

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 12666206305 in words is "twelve billion, six hundred sixty-six million, two hundred six thousand, three hundred five".