165897 has 6 divisors (see below), whose sum is σ = 239642. Its totient is φ = 110592.

The previous prime is 165887. The next prime is 165901. The reversal of 165897 is 798561.

It can be written as a sum of positive squares in only one way, i.e., 145161 + 20736 = 381^2 + 144^2 .

It is not a de Polignac number, because 165897 - 2⁶ = 165833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9208 + ... + 9225.

165897 is a Friedman number, since it can be written as 9+(7+5)^6/18, using all its digits and the basic arithmetic operations.

2¹⁶⁵⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

165897 is a deficient number, since it is larger than the sum of its proper divisors (73745).

165897 is a wasteful number, since it uses less digits than its factorization.

165897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18439 (or 18436 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 165897 is about 407.3045543571. The cubic root of 165897 is about 54.9472773001.

The spelling of 165897 in words is "one hundred sixty-five thousand, eight hundred ninety-seven".