A good port for my nodejs game?

I am making a nodejs game. I have tried many ports(25565,12100,2754,6112,1337 and other random ports). All of them worked serverside, however clientside they were sometimes blocked by firewalls or (what is my biggest concern) used by something else what increased latency alot. So what I need is a port that is(if possible) mostly open and that got nothing using it that would disturb my game's connection. Any suggestions for good ports?