Prime Number

A prime number is defined as a number which can be only divisible by 1 and that number itself. That number cannot be divisible by any other number. So if we try to divide that number by any other number between one and that number , we will get a remainder. According to the prime number definition number one ( 1 ) wont consider as a primer number. The smallest primer number is 2 .

See is a list of primer number below 50
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47,51

Here is a sample PHP script program to create a list of prime numbers
In this example we are going to print first 20 prime numbers.

<?php
$count = 0 ;
$number = 2 ;
while ($count < 20 )
{
$div_count=0;
for ( $i=1;$i<=$number;$i++)
{
if (($number%$i)==0)
{
$div_count++;
}
}
if ($div_count<3)
{
echo $number." , ";
$count=$count+1;
}
$number=$number+1;
}
?>

Output

2 , 3 , 5 , 7 , 11 , 13 , 17 , 19 , 23 , 29 , 31 , 37 , 41 , 43 , 47 , 53 , 59 , 61 , 67 , 71 ,