320565 has 32 divisors (see below), whose sum is σ = 608256. Its totient is φ = 141120.

The previous prime is 320563. The next prime is 320591. The reversal of 320565 is 565023.

It is not a de Polignac number, because 320565 - 2¹ = 320563 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 320565.

It is not an unprimeable number, because it can be changed into a prime (320561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4480 + ... + 4550.

It is an arithmetic number, because the mean of its divisors is an integer number (19008).

2³²⁰⁵⁶⁵ is an apocalyptic number.

320565 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

320565 is a deficient number, since it is larger than the sum of its proper divisors (287691).

320565 is a wasteful number, since it uses less digits than its factorization.

320565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129.

The product of its (nonzero) digits is 900, while the sum is 21.

The square root of 320565 is about 566.1845988721. The cubic root of 320565 is about 68.4392698819.

Adding to 320565 its reverse (565023), we get a palindrome (885588).

The spelling of 320565 in words is "three hundred twenty thousand, five hundred sixty-five".