Convert seconds into HH:MM:SS in Informix
Using the below sql, I managed to give exactly what I am looking for. I used the number 6346 to display the output populating hours, minutes and seconds.
Query used:
select lpad(floor(6346 / 60 / 60),2,'0') || ':' || lpad(mod(6346/60, 60), 2, '0') || ':' || lpad(mod(6346,60), 2, '0') as run_duration_time from systables

Output:
01:45:46

Another example without hours:
select lpad(floor(1000 / 60 / 60),2,'0') || ':' || lpad(mod(1000/60, 60), 2, '0') || ':' || lpad(mod(1000, 60), 2, '0') as run_duration_time

from systables
Output:
00:16:40

Another example without hours and minutes:
select lpad(floor(45 / 60 / 60),2,'0') || ':' || lpad(mod(45/60, 60), 2, '0') || ':' || lpad(mod(45, 60), 2, '0') as run_duration_time

from systables
Output:
00:00:45