166686617 has 2 divisors, whose sum is σ = 166686618. Its totient is φ = 166686616.

The previous prime is 166686593. The next prime is 166686661. The reversal of 166686617 is 716686661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132802576 + 33884041 = 11524^2 + 5821^2 .

It is an emirp because it is prime and its reverse (716686661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166686617 - 2¹⁴ = 166670233 is a prime.

It is not a weakly prime, because it can be changed into another prime (166686697) 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, 83343308 + 83343309.

It is an arithmetic number, because the mean of its divisors is an integer number (83343309).

Almost surely, 2^166686617 is an apocalyptic number.

It is an amenable number.

166686617 is a deficient number, since it is larger than the sum of its proper divisors (1).

166686617 is an equidigital number, since it uses as much as digits as its factorization.

166686617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 47.

The square root of 166686617 is about 12910.7171373243. The cubic root of 166686617 is about 550.3431654561.

The spelling of 166686617 in words is "one hundred sixty-six million, six hundred eighty-six thousand, six hundred seventeen".