How to Know My Own Android Number
If you do not know your Android mobile phone number, you can obtain the number from the phone itself. All of the information about your phone is stored within its settings. By knowing where to look, you can find the number without the need to call another phone to obtain it from caller ID. Even if the phone number was just changed seconds ago, the correct number will be displayed on your phone.
Press "Home" on your Android mobile phone. The home screen will be displayed.
Press "Menu" to view the expanded home screen.
Tap "Settings," then tap "About Phone."
Tap "Phone Identity," then tap "Phone Number." The Android's 10-digit number will be displayed.