321865 has 4 divisors (see below), whose sum is σ = 386244. Its totient is φ = 257488.

The previous prime is 321851. The next prime is 321889. The reversal of 321865 is 568123.

It is a happy number.

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 190096 + 131769 = 436^2 + 363^2 .

It is a cyclic number.

It is not a de Polignac number, because 321865 - 2⁵ = 321833 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 321865.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32182 + ... + 32191.

It is an arithmetic number, because the mean of its divisors is an integer number (96561).

2³²¹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

321865 is a deficient number, since it is larger than the sum of its proper divisors (64379).

321865 is an equidigital number, since it uses as much as digits as its factorization.

321865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64378.

The product of its digits is 1440, while the sum is 25.

The square root of 321865 is about 567.3314727741. The cubic root of 321865 is about 68.5316599346.

Adding to 321865 its reverse (568123), we get a palindrome (889988).

The spelling of 321865 in words is "three hundred twenty-one thousand, eight hundred sixty-five".