12644100991 has 2 divisors, whose sum is σ = 12644100992. Its totient is φ = 12644100990.

The previous prime is 12644100971. The next prime is 12644101003. The reversal of 12644100991 is 19900144621.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12644100991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12644100991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12644100941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6322050495 + 6322050496.

It is an arithmetic number, because the mean of its divisors is an integer number (6322050496).

Almost surely, 2^12644100991 is an apocalyptic number.

12644100991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12644100991 is an equidigital number, since it uses as much as digits as its factorization.

12644100991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 37.

The spelling of 12644100991 in words is "twelve billion, six hundred forty-four million, one hundred thousand, nine hundred ninety-one".