12665126665 has 4 divisors (see below), whose sum is σ = 15198152004. Its totient is φ = 10132101328.

The previous prime is 12665126653. The next prime is 12665126681. The reversal of 12665126665 is 56662156621.

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 1909777401 + 10755349264 = 43701^2 + 103708^2 .

It is a cyclic number.

It is not a de Polignac number, because 12665126665 - 2³³ = 4075192073 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, 1266512662 + ... + 1266512671.

It is an arithmetic number, because the mean of its divisors is an integer number (3799538001).

Almost surely, 2^12665126665 is an apocalyptic number.

It is an amenable number.

12665126665 is a deficient number, since it is larger than the sum of its proper divisors (2533025339).

12665126665 is an equidigital number, since it uses as much as digits as its factorization.

12665126665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2533025338.

The product of its digits is 777600, while the sum is 46.

The spelling of 12665126665 in words is "twelve billion, six hundred sixty-five million, one hundred twenty-six thousand, six hundred sixty-five".