166691677 has 2 divisors, whose sum is σ = 166691678. Its totient is φ = 166691676.

The previous prime is 166691669. The next prime is 166691683. The reversal of 166691677 is 776196661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155226681 + 11464996 = 12459^2 + 3386^2 .

It is a cyclic number.

It is not a de Polignac number, because 166691677 - 2³ = 166691669 is a prime.

It is a super-2 number, since 2×166691677² = 55572230362144658, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 166691677.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166611677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83345838 + 83345839.

It is an arithmetic number, because the mean of its divisors is an integer number (83345839).

Almost surely, 2^166691677 is an apocalyptic number.

It is an amenable number.

166691677 is a deficient number, since it is larger than the sum of its proper divisors (1).

166691677 is an equidigital number, since it uses as much as digits as its factorization.

166691677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571536, while the sum is 49.

The square root of 166691677 is about 12910.9130970664. The cubic root of 166691677 is about 550.3487342060.

The spelling of 166691677 in words is "one hundred sixty-six million, six hundred ninety-one thousand, six hundred seventy-seven".