En supposant que vous souhaitiez convertir 492 minutes :
select to_char(trunc(sysdate) + 492/24/60, 'hh24:mi') from dual;
Si vous voulez une fonction :
create or replace
function tq84_convert_minutes_hh24mm (p_minutes in number)
return varchar2 is
begin
return to_char (trunc(sysdate) + p_minutes / 24/60, 'hh24:mi');
end tq84_convert_minutes_hh24mm;
/
Plus tard...
begin
dbms_output.put_line (tq84_convert_minutes_hh24mm(492));
end;
/