Call Center Queues and Inbound numbers are usually assigned together when they are first purchased. These numbers can be reassigned to different queues as well. To keep track of which numbers are assigned to which queues, you can check them under the queue settings.
From the Dashboard, click on Call Center and select Call Center Queues from the drop down.
In the Show Queues Section, click on the Action Button of the Queue, and select Settings from the drop down
Select the Assigned Numbers Tab and it will show the list of Inbound numbers assigned to this Call Center Queue