289665 has 24 divisors (see below), whose sum is σ = 517608. Its totient is φ = 149760.

The previous prime is 289657. The next prime is 289669. The reversal of 289665 is 566982.

289665 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in 4 ways, for example, as 1296 + 288369 = 36^2 + 537^2 .

It is not a de Polignac number, because 289665 - 2³ = 289657 is a prime.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 289665.

It is not an unprimeable number, because it can be changed into a prime (289669) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1767 + ... + 1923.

It is an arithmetic number, because the mean of its divisors is an integer number (21567).

2²⁸⁹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

289665 is a deficient number, since it is larger than the sum of its proper divisors (227943).

289665 is a wasteful number, since it uses less digits than its factorization.

289665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209 (or 206 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 289665 is about 538.2053511440. The cubic root of 289665 is about 66.1655622979.

The spelling of 289665 in words is "two hundred eighty-nine thousand, six hundred sixty-five".