$ sudo apt-get remove atril 

Uninstall atril including dependent package

If you would like to remove atril and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove atril 

Use Purging atril

If you use with purge options to atril package all the configuration and dependent packages will be removed.

$ sudo apt-get purge atril 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove atril 

See Also,