Is 423 a prime number? What are the divisors of 423?

## Parity of 423

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

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## Is 423 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 423 is about 20.567.

Thus, the square root of 423 is not an integer, and therefore 423 is not a square number.

## What is the square number of 423?

The square of a number (here 423) is the result of the product of this number (423) by itself (i.e., 423 × 423); the square of 423 is sometimes called "raising 423 to the power 2", or "423 squared".

The square of 423 is 178 929 because 423 × 423 = 4232 = 178 929.

As a consequence, 423 is the square root of 178 929.

## Number of digits of 423

423 is a number with 3 digits.

## What are the multiples of 423?

The multiples of 423 are all integers evenly divisible by 423, that is all numbers such that the remainder of the division by 423 is zero. There are infinitely many multiples of 423. The smallest multiples of 423 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 423). 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 20.567). 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 423

• Preceding numbers: …421, 422
• Following numbers: 424, 425

### Nearest numbers from 423

• Preceding prime number: 421
• Following prime number: 431
Find out whether some integer is a prime number