Open the Phone app
Tap the menu or settings icon
Look for My phone number, About phone, or SIM status
Check the Contacts app for your own contact card
Go to Settings
Tap About phone or About device
Tap Status or SIM status
Find Phone number or My phone number
Check the SIM card details if the number is stored there
Call or text another phone and see the displayed number
Use a carrier app or account page to view the number