Connected to:
Oracle9i Enterprise Edition Release 9.2.0.8.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.8.0 - Production

SQL> create table TEST11 (COL1 NUMBER(*,0));

Table created.

SQL>
SQL> INSERT INTO test11 VALUES (9999999999999999);

1 row created.

SQL>
SQL> SELECT COL1 FROM TEST11;

      COL1
----------
1.0000E+16

SQL>
SQL> SELECT to_char(COL1) FROM TEST11;

TO_CHAR(COL1)
----------------------------------------
9999999999999999

SQL> column col1 format 999999999999999999999
SQL> SELECT COL1 FROM TEST11;

                  COL1
----------------------
      9999999999999999

SQL>