12345666706661 has 2 divisors, whose sum is σ = 12345666706662. Its totient is φ = 12345666706660.

The previous prime is 12345666706643. The next prime is 12345666706717. The reversal of 12345666706661 is 16660766654321.

12345666706661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11320903269025 + 1024763437636 = 3364655^2 + 1012306^2 .

It is a cyclic number.

It is not a de Polignac number, because 12345666706661 - 2¹⁰ = 12345666705637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12345666706661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12345666706621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6172833353330 + 6172833353331.

It is an arithmetic number, because the mean of its divisors is an integer number (6172833353331).

Almost surely, 2^{12345666706661} is an apocalyptic number.

It is an amenable number.

12345666706661 is a deficient number, since it is larger than the sum of its proper divisors (1).

12345666706661 is an equidigital number, since it uses as much as digits as its factorization.

12345666706661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39191040, while the sum is 59.

The spelling of 12345666706661 in words is "twelve trillion, three hundred forty-five billion, six hundred sixty-six million, seven hundred six thousand, six hundred sixty-one".