165985 has 8 divisors (see below), whose sum is σ = 201960. Its totient is φ = 130944.

The previous prime is 165983. The next prime is 166013. The reversal of 165985 is 589561.

It can be written as a sum of positive squares in 4 ways, for example, as 5184 + 160801 = 72^2 + 401^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 165985 - 2¹ = 165983 is a prime.

165985 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 165985.

It is not an unprimeable number, because it can be changed into a prime (165983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 259 + ... + 631.

It is an arithmetic number, because the mean of its divisors is an integer number (25245).

2¹⁶⁵⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

165985 is a deficient number, since it is larger than the sum of its proper divisors (35975).

165985 is an equidigital number, since it uses as much as digits as its factorization.

165985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467.

The product of its digits is 10800, while the sum is 34.

The square root of 165985 is about 407.4125673074. The cubic root of 165985 is about 54.9569911702.

The spelling of 165985 in words is "one hundred sixty-five thousand, nine hundred eighty-five".