165745 has 4 divisors (see below), whose sum is σ = 198900. Its totient is φ = 132592.

The previous prime is 165721. The next prime is 165749. The reversal of 165745 is 547561.

165745 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 128881 + 36864 = 359^2 + 192^2 .

It is a cyclic number.

It is not a de Polignac number, because 165745 - 2⁵ = 165713 is a prime.

165745 is a lucky number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (165749) 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, 16570 + ... + 16579.

It is an arithmetic number, because the mean of its divisors is an integer number (49725).

2¹⁶⁵⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

165745 is a deficient number, since it is larger than the sum of its proper divisors (33155).

165745 is an equidigital number, since it uses as much as digits as its factorization.

165745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33154.

The product of its digits is 4200, while the sum is 28.

The square root of 165745 is about 407.1179190358. The cubic root of 165745 is about 54.9304907032.

The spelling of 165745 in words is "one hundred sixty-five thousand, seven hundred forty-five".