12957991 has 2 divisors, whose sum is σ = 12957992. Its totient is φ = 12957990.

The previous prime is 12957953. The next prime is 12958003. The reversal of 12957991 is 19975921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12957991 - 2¹⁵ = 12925223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12957911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6478995 + 6478996.

It is an arithmetic number, because the mean of its divisors is an integer number (6478996).

Almost surely, 2^12957991 is an apocalyptic number.

12957991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12957991 is an equidigital number, since it uses as much as digits as its factorization.

12957991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51030, while the sum is 43.

The square root of 12957991 is about 3599.7209614080. The cubic root of 12957991 is about 234.8799205449.

The spelling of 12957991 in words is "twelve million, nine hundred fifty-seven thousand, nine hundred ninety-one".