243321 has 16 divisors (see below), whose sum is σ = 370944. Its totient is φ = 140544.

The previous prime is 243311. The next prime is 243343. The reversal of 243321 is 123342.

It is not a de Polignac number, because 243321 - 2¹⁴ = 226937 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 243321.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 243321.

It is not an unprimeable number, because it can be changed into a prime (243301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 480 + ... + 846.

It is an arithmetic number, because the mean of its divisors is an integer number (23184).

2²⁴³³²¹ is an apocalyptic number.

It is an amenable number.

243321 is a deficient number, since it is larger than the sum of its proper divisors (127623).

243321 is a wasteful number, since it uses less digits than its factorization.

243321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400.

The product of its digits is 144, while the sum is 15.

The square root of 243321 is about 493.2757849317. The cubic root of 243321 is about 62.4299802517.

Adding to 243321 its reverse (123342), we get a palindrome (366663).

The spelling of 243321 in words is "two hundred forty-three thousand, three hundred twenty-one", and thus it is an iban number.