Converting a remainder to int to str

[tester_V]

what I actually need is to have all the "hours" added without converting it to days.

if I ran this script the outcome is "18:53:27" but it should be "138:53:27"

sec = 500007
sec_value = int(sec % (24 * 3600))
hour_value = str(int(sec_value // 3600))
sec_value %= (int(3600))
min = str(int(sec_value // 60))
sec_value %= 60
print(hour_value+":"+min+":"+str(sec_value))

Thank you!