You can convert numeric values to character strings by using the CAST(value AS CHAR) function as shown in the following examples:
SELECT CAST(4123.45700 AS CHAR) FROM DUAL;
4123.45700
-- How to get rid of the last 2 '0's?
SELECT CAST(4.12345700E+3 AS CHAR) FROM DUAL;
4123.457
SELECT CAST(1/3 AS CHAR);
0.3333
-- Very poor conversion