Is 403 a prime number? What are the divisors of 403?

## Parity of 403

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

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## Is 403 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 403 is about 20.075.

Thus, the square root of 403 is not an integer, and therefore 403 is not a square number.

## What is the square number of 403?

The square of a number (here 403) is the result of the product of this number (403) by itself (i.e., 403 × 403); the square of 403 is sometimes called "raising 403 to the power 2", or "403 squared".

The square of 403 is 162 409 because 403 × 403 = 4032 = 162 409.

As a consequence, 403 is the square root of 162 409.

## Number of digits of 403

403 is a number with 3 digits.

## What are the multiples of 403?

The multiples of 403 are all integers evenly divisible by 403, that is all numbers such that the remainder of the division by 403 is zero. There are infinitely many multiples of 403. The smallest multiples of 403 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 403). 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 20.075). 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 403

• Preceding numbers: …401, 402
• Following numbers: 404, 405

### Nearest numbers from 403

• Preceding prime number: 401
• Following prime number: 409
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