Instead of using mobile number to proceed with 2-factor authentication you can use Duo Mobile application.
To configure it open the next link https://myaccount.google.com/signinoptions/two-step-verification and click at Set up alternative second step → Authenticator app → Set up
Scan a QR-code with your Duo Mobile
At the next step enter the code that Duo Mobile generate for you
That's all, now Duo Mobile is the main 2-factor authentiocation method.
