165573 has 6 divisors (see below), whose sum is σ = 239174. Its totient is φ = 110376.

The previous prime is 165569. The next prime is 165587. The reversal of 165573 is 375561.

165573 is a `hidden beast` number, since 1 + 655 + 7 + 3 = 666.

165573 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in only one way, i.e., 161604 + 3969 = 402^2 + 63^2 .

It is not a de Polignac number, because 165573 - 2² = 165569 is a prime.

It is a Duffinian number.

It is a Curzon number.

165573 is a lucky number.

It is a congruent number.

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 5 ways as a sum of consecutive naturals, for example, 9190 + ... + 9207.

2¹⁶⁵⁵⁷³ is an apocalyptic number.

It is an amenable number.

165573 is a deficient number, since it is larger than the sum of its proper divisors (73601).

165573 is a wasteful number, since it uses less digits than its factorization.

165573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18403 (or 18400 counting only the distinct ones).

The product of its digits is 3150, while the sum is 27.

The square root of 165573 is about 406.9066231951. The cubic root of 165573 is about 54.9114829614.

Adding to 165573 its sum of digits (27), we get a triangular number (165600 = T₅₇₅).

It can be divided in two parts, 1655 and 73, that added together give a cube (1728 = 12³).

The spelling of 165573 in words is "one hundred sixty-five thousand, five hundred seventy-three".