12456991 has 2 divisors, whose sum is σ = 12456992. Its totient is φ = 12456990.

The previous prime is 12456943. The next prime is 12457001. The reversal of 12456991 is 19965421.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12456991 - 2¹¹ = 12454943 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12456991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12456911) 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, 6228495 + 6228496.

It is an arithmetic number, because the mean of its divisors is an integer number (6228496).

Almost surely, 2^12456991 is an apocalyptic number.

12456991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12456991 is an equidigital number, since it uses as much as digits as its factorization.

12456991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 37.

The square root of 12456991 is about 3529.4462738509. The cubic root of 12456991 is about 231.8129623608.

The spelling of 12456991 in words is "twelve million, four hundred fifty-six thousand, nine hundred ninety-one".