I dont know it this work in SQLServer, but in Oracle you can do:

select to_char (to_date(round(140000/1000), 'SSSSS' ), 'HH24:MI:SS') AS HMS from dual;

If you have more than 86399 seconds (seconds in a day) you must modify de sentence to detect that and add 24 hours to the result.

Best regards.

Ignacio