How to prevent unauthorized access and changes via TouchScreen AirCard 781S

I have recently bought a AirCard 781S AT&T unlocked 4G router. The web interface is fine however I need to ask the following queries and a possible soluiton for them :

1. In the main web interface login screen there is only the need for username, not a user name and password, anyone who knows the default username (attadmin - by searching on the web) can easily login in your router and mess up the settings. How to prevent any such unauthorized access.

2.  There is no way to protect access to touch screen interface. If the router is placed in a office space, anyone can access the touch screen to go in the settings and do anything including resetting the configuration. Is there any way to protect the touch screen with a password or otherwise.

Would appreciate a quick response to the above-mentioned.

Thanks.