Right-clicking server properties when inside Pervasive Control Center brings up a list of properties of which "Communication Protocols" contains the port number.
However, when I click on Communication Protocols the panel with the settings is nearly blank because of some redraw problem. After clicking repeatedly on the property list, the page showed properly and I was able to see the port number.
Now I need to set up the router's port forwarding to achieve remote access and then start testing the setup via PHP ODBC queries.