165851 has 16 divisors (see below), whose sum is σ = 211200. Its totient is φ = 127008.

The previous prime is 165833. The next prime is 165857. The reversal of 165851 is 158561.

It is a de Polignac number, because none of the positive numbers 2^k-165851 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165851.

It is not an unprimeable number, because it can be changed into a prime (165857) 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 15 ways as a sum of consecutive naturals, for example, 3836 + ... + 3878.

It is an arithmetic number, because the mean of its divisors is an integer number (13200).

2¹⁶⁵⁸⁵¹ is an apocalyptic number.

165851 is a deficient number, since it is larger than the sum of its proper divisors (45349).

165851 is a wasteful number, since it uses less digits than its factorization.

165851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98.

The product of its digits is 1200, while the sum is 26.

The square root of 165851 is about 407.2480816407. The cubic root of 165851 is about 54.9421982282.

The spelling of 165851 in words is "one hundred sixty-five thousand, eight hundred fifty-one".