166217617 has 2 divisors, whose sum is σ = 166217618. Its totient is φ = 166217616.

The previous prime is 166217581. The next prime is 166217621. The reversal of 166217617 is 716712661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 141705216 + 24512401 = 11904^2 + 4951^2 .

It is a cyclic number.

It is not a de Polignac number, because 166217617 - 2¹⁹ = 165693329 is a prime.

It is not a weakly prime, because it can be changed into another prime (166217677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83108808 + 83108809.

It is an arithmetic number, because the mean of its divisors is an integer number (83108809).

Almost surely, 2^166217617 is an apocalyptic number.

It is an amenable number.

166217617 is a deficient number, since it is larger than the sum of its proper divisors (1).

166217617 is an equidigital number, since it uses as much as digits as its factorization.

166217617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 37.

The square root of 166217617 is about 12892.5411381930. The cubic root of 166217617 is about 549.8265204939.

The spelling of 166217617 in words is "one hundred sixty-six million, two hundred seventeen thousand, six hundred seventeen".