165520 has 20 divisors (see below), whose sum is σ = 385020. Its totient is φ = 66176.

The previous prime is 165511. The next prime is 165523. The reversal of 165520 is 25561.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 41616 + 123904 = 204^2 + 352^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (165523) 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, 955 + ... + 1114.

It is an arithmetic number, because the mean of its divisors is an integer number (19251).

2¹⁶⁵⁵²⁰ is an apocalyptic number.

165520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165520 is an abundant number, since it is smaller than the sum of its proper divisors (219500).

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

165520 is a wasteful number, since it uses less digits than its factorization.

165520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2082 (or 2076 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 165520 is about 406.8414924759. The cubic root of 165520 is about 54.9056232717.

The spelling of 165520 in words is "one hundred sixty-five thousand, five hundred twenty".