66666317 has 2 divisors, whose sum is σ = 66666318. Its totient is φ = 66666316.

The previous prime is 66666311. The next prime is 66666319. The reversal of 66666317 is 71366666.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43903876 + 22762441 = 6626^2 + 4771^2 .

It is a cyclic number.

It is not a de Polignac number, because 66666317 - 2¹² = 66662221 is a prime.

Together with 66666319, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66666311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333158 + 33333159.

It is an arithmetic number, because the mean of its divisors is an integer number (33333159).

Almost surely, 2^66666317 is an apocalyptic number.

It is an amenable number.

66666317 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666317 is an equidigital number, since it uses as much as digits as its factorization.

66666317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 41.

The square root of 66666317 is about 8164.9443966263. The cubic root of 66666317 is about 405.4794241226.

The spelling of 66666317 in words is "sixty-six million, six hundred sixty-six thousand, three hundred seventeen".