See the number_format function,
$number = number_format($number, 0, '', '.');
// change 70000000 to 70.000.000 etc.
// ex. with a number set
$numbers = array(70000000, 75000000, 300000);
foreach ($numbers as $number) {
echo number_format($number, 0, '', '.') . '<br>';
}
solved Add “.”(dot) in a Numbers [duplicate]