There shouldn't be an issue if you wall mount the router. The trick is to make sure the chassis has the screw holes in the proper place so that you can utilize the rack mount brackets for this purpose. If not, you'll have to figure out a way to properly secure the router. The below link references wall mounting other 4000 series model routers:
http://www.cisco.com/c/en/us/td/docs/routers/access/4400/hardware/installation/guide4400-4300/C4400_isr/Install_Connect.html
Just make sure airflow and accessibility is not compromised.
Hope this helps.