165863 has 4 divisors (see below), whose sum is σ = 169440. Its totient is φ = 162288.

The previous prime is 165857. The next prime is 165877. The reversal of 165863 is 368561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165863 - 2⁶ = 165799 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1718 + ... + 1811.

It is an arithmetic number, because the mean of its divisors is an integer number (42360).

2¹⁶⁵⁸⁶³ is an apocalyptic number.

165863 is a deficient number, since it is larger than the sum of its proper divisors (3577).

165863 is an equidigital number, since it uses as much as digits as its factorization.

165863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3576.

The product of its digits is 4320, while the sum is 29.

The square root of 165863 is about 407.2628144086. The cubic root of 165863 is about 54.9435232940.

The spelling of 165863 in words is "one hundred sixty-five thousand, eight hundred sixty-three".