# Perl Program to Check Whether a Number is Prime or Not

If you are searching for prime number program in Perl, here ends your search. Before going to the program part, it is vital to understand a prime number.It is a natural number which is larger than 1 but has no positive divisors other than that number and 1. But a number which is not prime and greater than 1 is called as “composite” number.

Between 1 to 100, there are 25 prime numbers. They are: 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61, 67,71,73,79,83,89,97

## Perl program to find prime numbers

**PROBLEM DEFINITION**

Write a program to check whether a number is prime or not.

**ALGORITHM**

Step 1: Start

Step 2: Read the number to n.

Step 3: Initialize d (flag) to 0.

Step 4: if n is equal to 2,print number is prime.

Step 5: check if n%c=0,set flag=1

Step 6: if flag=1,break from loop n print not prime , else print prime.

Step 7: Stop

**Perl program to find prime numbers**

print “Enter a numbern”;

$n=<>;

$d=0;

if($n==2)

{

print “Prime number.n”;

}

else

{

for($c=2;$c<=$n-1;$c++)

{

if($n%$c==0)

{

$d=1;

break;

}

}

if($d==1)

{

print “Not prime.n”;

}

else

{

print “Prime number.n”;

}

}

**OUTPUT**

Enter a number

5

Prime Number

**CONCLUSION**

The program was executed successfully.