SQL>
SQL> select 90101, dump(reverse(90101),16) from dual
2 union all
3 select 90102, dump(reverse(90102),16) from dual
4 union all
5 select 90103, dump(reverse(90103),16) from dual
6 /
90101 DUMP(REVERSE(90101),1
---------- ---------------------
90101 Typ=2 Len=4: 2,2,a,c3
90102 Typ=2 Len=4: 3,2,a,c3
90103 Typ=2 Len=4: 4,2,a,c3
SQL>