12668342815321 has 2 divisors, whose sum is σ = 12668342815322. Its totient is φ = 12668342815320.

The previous prime is 12668342815313. The next prime is 12668342815351. The reversal of 12668342815321 is 12351824386621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7963937982025 + 4704404833296 = 2822045^2 + 2168964^2 .

It is a cyclic number.

It is not a de Polignac number, because 12668342815321 - 2³ = 12668342815313 is a prime.

It is not a weakly prime, because it can be changed into another prime (12668342815351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6334171407660 + 6334171407661.

It is an arithmetic number, because the mean of its divisors is an integer number (6334171407661).

Almost surely, 2^{12668342815321} is an apocalyptic number.

It is an amenable number.

12668342815321 is a deficient number, since it is larger than the sum of its proper divisors (1).

12668342815321 is an equidigital number, since it uses as much as digits as its factorization.

12668342815321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3317760, while the sum is 52.

The spelling of 12668342815321 in words is "twelve trillion, six hundred sixty-eight billion, three hundred forty-two million, eight hundred fifteen thousand, three hundred twenty-one".