If you have an iPhone and a Mac or iPad, you can link your phone number to your iCloud account to send and receive calls and messages from the same number on both devices.
Add a new or existing number to iOS
You need to make sure your devices are logged in to the same iCloud account for everything to sync properly.
The process is the same for all iOS devices, but you need to activate your existing number on your iPhone first. On your phone, open the Settings app.
Touch the category labeled "Messages".
Make sure you are logged in and have iMessage turned on. Scroll down and tap "Send and receive."
You may be asked to log in with your Apple ID to use it with iMessage. If so, sign in.
When logged in, make sure your phone number is highlighted under "You can get iMessages to and reply from." If it is, you are good for iMessage.
FaceTime still needs setup though. Return to the main window and click on FaceTime settings.
Make sure you use your Apple ID for FaceTime and activate your number under "You can be reached by FaceTime at."
Now that your iPhone shares its phone number, you can enable the same settings on your iPad or iPod Touch to synchronize messages between devices.
Add your phone number to macOS
Now that your phone is configured, you can move to your Mac. Open messages, and you will be asked to log in if you have never used it before. Open the message settings by pressing Command + Command or by selecting "Settings" from the "Messages" drop-down menu in the top menu.
If you set your phone correctly, see your phone number under "You can be reached for messages at." It will probably be enabled by default.
This sends your Mac all iMessages sent to your phone number. However, this does not include text messages; for that you must enable text message forwarding.
RELATED: How to configure text message forwarding on your Mac or iPad
For FaceTime, the process is the same. Open the FaceTime settings, and you will see the same window with a checkbox next to your phone number.
This will link your phone and Mac for FaceTime calls, but if you want to receive mobile calls on your Mac, you must enable call forwarding.
RELATED: How to make and answer phone calls on your Mac
Delete a number
To delete a number, uncheck the box next to it in iMessage and The FaceTime settings on the device you want to delete. This will prevent you from receiving future calls and texts on that device.
If you want to remove it from your iCloud account altogether, you must turn off your iPhone. If you do not have the phone (for example, if you sold it without first throwing it or if it was stolen), you can change your Apple ID password to force the phone to log out. While it's a stolen phone, you can always wipe it remotely with Find My iPhone, which solves the problem in the process.