12657691 has 2 divisors, whose sum is σ = 12657692. Its totient is φ = 12657690.

The previous prime is 12657637. The next prime is 12657721. The reversal of 12657691 is 19675621.

12657691 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12657691 - 2⁷ = 12657563 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12657691.

It is not a weakly prime, because it can be changed into another prime (12657611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6328845 + 6328846.

It is an arithmetic number, because the mean of its divisors is an integer number (6328846).

Almost surely, 2^12657691 is an apocalyptic number.

12657691 is a deficient number, since it is larger than the sum of its proper divisors (1).

12657691 is an equidigital number, since it uses as much as digits as its factorization.

12657691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 37.

The square root of 12657691 is about 3557.7648882409. The cubic root of 12657691 is about 233.0512820989.

The spelling of 12657691 in words is "twelve million, six hundred fifty-seven thousand, six hundred ninety-one".