how to get numbers for divisibe php code example

Example 1: is number divisible by 3 php

if($number % 15 == 0)  {
    echo "BY3 AND 5";
} elseif ($number % 5 == 0) {
    echo "BY5";
} elseif ($number % 3 == 0) {
    echo "BY3";
}

Example 2: php if divisible by 30

if ($variable % 30 == 0) {
    echo 'This number is divisible by 30.';
};