convert seconds to HH:MI:SS for large numbers

[NIckman]

Hi
I pasted wrong one.
this is the query i am running.

select emp_group||','||
to_char(to_date(sum(chktime),'sssss'),'hh24:mi:ss')
from emp,dept
where emp.id = dept.id
and emp_group='finance'
group by emp_group having sum(chktime) > 1;

if chktime is smaller number the same query works. if it is a larger numbers like 876543298 it is not working. how to solve this pl help. thx,N.

for larger numbers, I got his error.

ORA-01830: date format picture ends before converting entire input string