(defun integer-to-text (int)
  (format nil "~@(~A~)" (with-output-to-string (out)
                          (loop for n = int then (length c)
                                for c = (format nil "~R" n)
                                while (/= n 4)
                                do (format out "~A is ~R, " c (length c))
                                finally (format out "four is magic.")))))
(loop for n
       in '( -1 0 1 2 3 4 5 6 7 8 9 11 21 1995 1000000 1234567890 1100100100100 )
       do (print (integer-to-text n)))