If you run dropbear (SSH server) in OpenWRT, you can change the port on which it listens. You may want to do this for various reasons: to support http tunneling from a remote machine, avoid using the default port 22 to avoid attacks on that port. To do change the port in OpenWRT, modify the dropbear configuration in /etc/config/dropbear as follows.
option PasswordAuth 'on'
option Port '443'