Yes, substring would be the best solution here, so you would get:
$number = "1234567890";
$number_1 = substr($number, 0, 1);
$number_2 = substr($number, 2, 5);
$number_3 = substr($number, 6, 9);
And you can call them all seperatly like this:
echo "The first two numbers are: " . $number_1 . "<br>\n";
echo "The four numbers after that are: " . $number_2 . "<br>\n";
echo "The last four numbers are: " . $number_3 . "<br>\n";