166685 has 16 divisors (see below), whose sum is σ = 221616. Its totient is φ = 119808.

The previous prime is 166679. The next prime is 166693. The reversal of 166685 is 586661.

166685 = T₅₄ + T₅₅ + ... + T₁₀₄.

166685 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 27556 + 139129 = 166^2 + 373^2 .

It is a cyclic number.

It is not a de Polignac number, because 166685 - 2⁴ = 166669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3119 + ... + 3171.

It is an arithmetic number, because the mean of its divisors is an integer number (13851).

2¹⁶⁶⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

166685 is a deficient number, since it is larger than the sum of its proper divisors (54931).

166685 is a wasteful number, since it uses less digits than its factorization.

166685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112.

The product of its digits is 8640, while the sum is 32.

The square root of 166685 is about 408.2707435024. The cubic root of 166685 is about 55.0341385854.

The spelling of 166685 in words is "one hundred sixty-six thousand, six hundred eighty-five".