668169 has 20 divisors (see below), whose sum is σ = 1020756. Its totient is φ = 435456.

The previous prime is 668159. The next prime is 668179. The reversal of 668169 is 961866.

It is an interprime number because it is at equal distance from previous prime (668159) and next prime (668179).

It can be written as a sum of positive squares in 2 ways, for example, as 149769 + 518400 = 387^2 + 720^2 .

It is not a de Polignac number, because 668169 - 2⁴ = 668153 is a prime.

It is a super-2 number, since 2×668169² = 892899625122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5857 + ... + 5969.

2⁶⁶⁸¹⁶⁹ is an apocalyptic number.

It is an amenable number.

668169 is a deficient number, since it is larger than the sum of its proper divisors (352587).

668169 is a wasteful number, since it uses less digits than its factorization.

668169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 189 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 668169 is about 817.4160507355. The cubic root of 668169 is about 87.4236176959.

The spelling of 668169 in words is "six hundred sixty-eight thousand, one hundred sixty-nine".