Is 999 a prime number? What are the divisors of 999?

## Parity of 999

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

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## Is 999 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 999 is about 31.607.

Thus, the square root of 999 is not an integer, and therefore 999 is not a square number.

## What is the square number of 999?

The square of a number (here 999) is the result of the product of this number (999) by itself (i.e., 999 × 999); the square of 999 is sometimes called "raising 999 to the power 2", or "999 squared".

The square of 999 is 998 001 because 999 × 999 = 9992 = 998 001.

As a consequence, 999 is the square root of 998 001.

## Number of digits of 999

999 is a number with 3 digits.

## What are the multiples of 999?

The multiples of 999 are all integers evenly divisible by 999, that is all numbers such that the remainder of the division by 999 is zero. There are infinitely many multiples of 999. The smallest multiples of 999 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 999). 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 31.607). 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 999

### Nearest numbers from 999

• Preceding prime number: 997
• Following prime number: 1 009
Find out whether some integer is a prime number