Is 321 a prime number? What are the divisors of 321?

## Parity of 321

321 is an odd number, because it is not evenly divisible by 2.

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## Is 321 a perfect square number?

A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 321 is about 17.916.

Thus, the square root of 321 is not an integer, and therefore 321 is not a square number.

## What is the square number of 321?

The square of a number (here 321) is the result of the product of this number (321) by itself (i.e., 321 × 321); the square of 321 is sometimes called "raising 321 to the power 2", or "321 squared".

The square of 321 is 103 041 because 321 × 321 = 3212 = 103 041.

As a consequence, 321 is the square root of 103 041.

## Number of digits of 321

321 is a number with 3 digits.

## What are the multiples of 321?

The multiples of 321 are all integers evenly divisible by 321, that is all numbers such that the remainder of the division by 321 is zero. There are infinitely many multiples of 321. The smallest multiples of 321 are:

## How to determine whether an integer is a prime number?

To determine the primality of a number, several algorithms can be used. The most naive technique is to test all divisors strictly smaller to the number of which we want to determine the primality (here 321). First, we can eliminate all even numbers greater than 2 (and hence 4, 6, 8…). Then, we can stop this check when we reach the square root of the number of which we want to determine the primality (here the square root is about 17.916). Historically, the sieve of Eratosthenes (dating from the Greek mathematics) implements this technique in a relatively efficient manner.

More modern techniques include the sieve of Atkin, probabilistic algorithms, and the cyclotomic AKS test.

## Numbers near 321

• Preceding numbers: …319, 320
• Following numbers: 322, 323

### Nearest numbers from 321

• Preceding prime number: 317
• Following prime number: 331
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