12661833078217 has 2 divisors, whose sum is σ = 12661833078218. Its totient is φ = 12661833078216.

The previous prime is 12661833078197. The next prime is 12661833078269. The reversal of 12661833078217 is 71287033816621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9769194076041 + 2892639002176 = 3125571^2 + 1700776^2 .

It is a cyclic number.

It is not a de Polignac number, because 12661833078217 - 2³⁵ = 12627473339849 is a prime.

It is not a weakly prime, because it can be changed into another prime (12661833078287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6330916539108 + 6330916539109.

It is an arithmetic number, because the mean of its divisors is an integer number (6330916539109).

Almost surely, 2^{12661833078217} is an apocalyptic number.

It is an amenable number.

12661833078217 is a deficient number, since it is larger than the sum of its proper divisors (1).

12661833078217 is an equidigital number, since it uses as much as digits as its factorization.

12661833078217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4064256, while the sum is 55.

The spelling of 12661833078217 in words is "twelve trillion, six hundred sixty-one billion, eight hundred thirty-three million, seventy-eight thousand, two hundred seventeen".