Spelling numbers in PL/SQL

spell-number.sql

CREATE OR REPLACE FUNCTION spell_number(p_number IN NUMBER)
  RETURN VARCHAR2 AS
  TYPE myarray IS TABLE OF VARCHAR2(255);

  l_str myarray := myarray(
    '',
    ' thousand ',
    ' million ',
    ' billion ',
    ' trillion ',
    ' quadrillion ',
    ' quintillion ',
    ' sextillion ',
    ' septillion ',
    ' octillion ',
    ' nonillion ',
    ' decillion ',
    ' undecillion ',
    ' duodecillion '
  );
  l_num VARCHAR2(50) DEFAULT trunc(p_number);
  l_return VARCHAR2(4000);
BEGIN
  FOR i IN 1 .. l_str.count LOOP
    EXIT WHEN l_num IS NULL;
    IF (substr(l_num, length(l_num) - 2, 3) <> 0) THEN
      l_return :=
        to_char(to_date(substr(l_num, length(l_num) - 2, 3), 'J'), 'Jsp') || l_str(i) || l_return;
    END IF;
    l_num := substr(l_num, 1, length(l_num) - 3);
  END LOOP;
  RETURN l_return;
END;