A prime number is a natural positive number, that can have exactly two
factors, 1 and the number itself. Other wise its called composite
numbers. A prime number cannot be equally divisible by any other number, other than 1 and the number itself. When we consider the factor of a number, the set of natural number can be divided into two sets, prime numbers, composite numbers. The divisors of prime numbers are also natural. The collection of all prime numbers is infinite. Here we discussed the prime numbers up to 1000 only.

Prime numbers are those numbers that cannot be divided by any number except themselves and one.

## Properties of Prime Numbers

The following are some of properties of prime numbers, that is very helpful in finding prime numbers.

- The prime number can also be called odd prime number if we exclude 2 from the whole set, as 2 is the only even prime number.
- 1 is not considered as a prime number, as it doesn’t satisfy the definition of a prime number.
- Zero is also not considered as prime numbers, as its a whole number.

- Except for 5, there is no prime number that ends in 5.
- If the sum of the digits of a number is a multiple of 3, then it cannot be prime

## Prime Numbers up to 1000

Any prime number can be obtained by first trying to divide by 2, and remove all numbers that can be divided by 2. Next move to 3 and remove all numbers divisible by 3 . Repeat this process thought out. Instead of checking each number, its enough to check only till $\sqrt{1000}$ = $31.62$ $\sim 32$. This prime number chart to 1000 will help in keeping track of all the prime numbers up to 1000. In this manner, its possible to find the prime number till any number.

The following table gives the list of all the prime number up to 1000.