12956561819791 has 2 divisors, whose sum is σ = 12956561819792. Its totient is φ = 12956561819790.

The previous prime is 12956561819737. The next prime is 12956561819953. The reversal of 12956561819791 is 19791816565921.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12956561819791 - 2²³ = 12956553431183 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12956561819791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12956561819701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6478280909895 + 6478280909896.

It is an arithmetic number, because the mean of its divisors is an integer number (6478280909896).

Almost surely, 2^{12956561819791} is an apocalyptic number.

12956561819791 is a deficient number, since it is larger than the sum of its proper divisors (1).

12956561819791 is an equidigital number, since it uses as much as digits as its factorization.

12956561819791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73483200, while the sum is 70.

The spelling of 12956561819791 in words is "twelve trillion, nine hundred fifty-six billion, five hundred sixty-one million, eight hundred nineteen thousand, seven hundred ninety-one".