166639169 has 2 divisors, whose sum is σ = 166639170. Its totient is φ = 166639168.

The previous prime is 166639153. The next prime is 166639181. The reversal of 166639169 is 961936661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165894400 + 744769 = 12880^2 + 863^2 .

It is a cyclic number.

It is not a de Polignac number, because 166639169 - 2⁴ = 166639153 is a prime.

It is a super-2 number, since 2×166639169² = 55537225290021122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166630169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83319584 + 83319585.

It is an arithmetic number, because the mean of its divisors is an integer number (83319585).

Almost surely, 2^166639169 is an apocalyptic number.

It is an amenable number.

166639169 is a deficient number, since it is larger than the sum of its proper divisors (1).

166639169 is an equidigital number, since it uses as much as digits as its factorization.

166639169 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 47.

The square root of 166639169 is about 12908.8794633771. The cubic root of 166639169 is about 550.2909413862.

The spelling of 166639169 in words is "one hundred sixty-six million, six hundred thirty-nine thousand, one hundred sixty-nine".