66356317613 has 2 divisors, whose sum is σ = 66356317614. Its totient is φ = 66356317612.

The previous prime is 66356317609. The next prime is 66356317639. The reversal of 66356317613 is 31671365366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65980655689 + 375661924 = 256867^2 + 19382^2 .

It is a cyclic number.

It is not a de Polignac number, because 66356317613 - 2² = 66356317609 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66356317603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33178158806 + 33178158807.

It is an arithmetic number, because the mean of its divisors is an integer number (33178158807).

Almost surely, 2^66356317613 is an apocalyptic number.

It is an amenable number.

66356317613 is a deficient number, since it is larger than the sum of its proper divisors (1).

66356317613 is an equidigital number, since it uses as much as digits as its factorization.

66356317613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1224720, while the sum is 47.

The spelling of 66356317613 in words is "sixty-six billion, three hundred fifty-six million, three hundred seventeen thousand, six hundred thirteen".