PHP number formatting for decimal and thousand places

<?Php
$number=2512589.66785;
echo "Number = $number ";
echo "<br>With formating = ".number_format($number); //  2,512,590

// Three decimal place 
echo "<br>With formating = ".number_format($number,3); // 2,512,589.668 

// Three decimal place, '.' as decimal separator and # as thousand separator 
echo "<br>With formating = ".number_format($number,3,'.','#'); //2#512#589.668 

// Two decimal place, ',' as decimal separator and : as thousand separator 
echo "<br>With formating = ".number_format($number,2,',',':'); //2:512:589,67

// Two decimal place, '.' as decimal separator and , as thousand separator 
echo "<br>With formating = ".number_format($number,2,'.',','); //2,512,589.67
?>