function convert($num) //by olafurw [at] gmail.com
{
$s = array('', 'TH', 'M', 'B', 'TR', 'Q');
// , thousand, million, billion, trillion, quadrillion, etc
$e = floor(log($num)/log(1000));
return sprintf('%.2f '.$s[$e], ($num/pow(1000, floor($e))));
}