If that's not a thing you wish to occur (and you shouldn't), you can get around the issue by removing your telephone number from the site as well as setting two-factor verification up making use of an authentication app instead.
How To Delete Number Off Facebook
To eliminate your phone number from Facebook go to the Settings menu on your account (you get there by clicking the arrow at the top best side of the page) and then Your Facebook Information followed by Sight under the Gain access to Your Details label. Within that menu, you'll wish to choose Personal Info and after that Your Contact Information. When you see your contact number, struck that delete switch.
To Remove a smart phone number:
-Click in the leading right edge of your Facebook page.
-Click Settings, after that click Mobile in the left sidebar.
-Click Remove listed below the number you 'd like to Remove.
-Click Remove Phone to confirm.
Later, choose Protection and Login from that primary Settings page and after that Set up two-factor verification. From there you must be able to customize your two-factor Settings, especially so that you're utilizing an authenticator application (such as Google Verification) rather than your phone number for that added layer of security.