12399676561 has 2 divisors, whose sum is σ = 12399676562. Its totient is φ = 12399676560.

The previous prime is 12399676543. The next prime is 12399676669. The reversal of 12399676561 is 16567699321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11287787536 + 1111889025 = 106244^2 + 33345^2 .

It is an emirp because it is prime and its reverse (16567699321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12399676561 - 2⁷ = 12399676433 is a prime.

It is not a weakly prime, because it can be changed into another prime (12399676361) 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, 6199838280 + 6199838281.

It is an arithmetic number, because the mean of its divisors is an integer number (6199838281).

Almost surely, 2^12399676561 is an apocalyptic number.

It is an amenable number.

12399676561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12399676561 is an equidigital number, since it uses as much as digits as its factorization.

12399676561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3674160, while the sum is 55.

It can be divided in two parts, 1239 and 9676561, that added together give a triangular number (9677800 = T₄₃₉₉).

The spelling of 12399676561 in words is "twelve billion, three hundred ninety-nine million, six hundred seventy-six thousand, five hundred sixty-one".