165858 has 32 divisors (see below), whose sum is σ = 414720. Its totient is φ = 42960.

The previous prime is 165857. The next prime is 165877. The reversal of 165858 is 858561.

165858 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an alternating number because its digits alternate between odd and even.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 165858.

It is not an unprimeable number, because it can be changed into a prime (165857) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 283 + ... + 641.

It is an arithmetic number, because the mean of its divisors is an integer number (12960).

2¹⁶⁵⁸⁵⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207360).

165858 is an abundant number, since it is smaller than the sum of its proper divisors (248862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165858 is a wasteful number, since it uses less digits than its factorization.

165858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382.

The product of its digits is 9600, while the sum is 33.

The square root of 165858 is about 407.2566758201. The cubic root of 165858 is about 54.9429711910.

The spelling of 165858 in words is "one hundred sixty-five thousand, eight hundred fifty-eight".