165820 has 12 divisors (see below), whose sum is σ = 348264. Its totient is φ = 66320.

The previous prime is 165817. The next prime is 165829. The reversal of 165820 is 28561.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 165791 and 165800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4126 + ... + 4165.

It is an arithmetic number, because the mean of its divisors is an integer number (29022).

2¹⁶⁵⁸²⁰ is an apocalyptic number.

165820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165820 is an abundant number, since it is smaller than the sum of its proper divisors (182444).

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

165820 is a wasteful number, since it uses less digits than its factorization.

165820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8300 (or 8298 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 165820 is about 407.2100195231. The cubic root of 165820 is about 54.9387748456.

The spelling of 165820 in words is "one hundred sixty-five thousand, eight hundred twenty".