Number to Word Conversation

We currently have a requirement on a Report Designer layout to convert a Number to a Word.

So what I mean and as an example,  a number of ‘100’ to be converted to ‘One hundred’.

I have used the below SQL in a CF - which works fine.

WITH cte AS
(
  select '-100' AS num
  from dual

)
SELECT 
  num AS old_value,
  decode( sign( num ), -1, 'NEGATIVE ', 0, 'ZERO', NULL )
  || decode( sign( abs(num) ), +1, to_char( to_date( abs(TRUNC(num)),'J'),'JSP') )
  ||
  CASE
     WHEN INSTR (num, '.') > 0
     THEN  ' POINT ' || TO_CHAR (TO_DATE (TO_NUMBER (RPAD(SUBSTR(num, INSTR (num, '.') + 1)
                                                     ,2,'0')
                                                     ),'J'),'JSP')
     ELSE NULL
  END AS new_value
FROM cte;

But, if the number if I enter a number of  ‘-6313343’ I am getting this error message.

ORA-01854: Julian date must be between 1 and 5373484

Is anybody aware of any else that I could use to get the ‘number to word’ conversation working to allow me to use it in a layout?

Any help would be great!