165866 has 8 divisors (see below), whose sum is σ = 250560. Its totient is φ = 82348.

The previous prime is 165857. The next prime is 165877. The reversal of 165866 is 668561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305 + ... + 651.

It is an arithmetic number, because the mean of its divisors is an integer number (31320).

2¹⁶⁵⁸⁶⁶ is an apocalyptic number.

165866 is a deficient number, since it is larger than the sum of its proper divisors (84694).

165866 is a wasteful number, since it uses less digits than its factorization.

165866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588.

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

The square root of 165866 is about 407.2664975173. The cubic root of 165866 is about 54.9438545505.

The spelling of 165866 in words is "one hundred sixty-five thousand, eight hundred sixty-six".