Everytime I log in on a new device or browser I get the SMS text message with the 2nd step digits. It's pretty annoying. I already have the Google Authenticator to calculate my digits and it works great.
How to disable SMS?
You have to remove your primary phone number, which will disable 2-step authentication. Then, using the authenticator app from your phone, re-set up the 2-step authentication without setting a primary phone number. You can then add your phone number as a backup if you wish.