With Facebook's latest update just around here's how you can keep advertisers away from using your phone number on Facebook. However,there's very little thing on our part which we can do in order to avoid advertisers to use our phone number.
The following are some of the tips which we can do in order to stop advertisers from targeting us by our phone numbers.
If your using your phone, you can go to Settings and Privacy icon in the main screen's hamburger menu. You can find this on the bottom right of the screen for iOS users. After selecting settings you should then go to Personal Information. After going to the next screen click on phone number and select Remove. After clicking this, you will get a confirmation email shortly.
If you are using Desktop, go to settings link on the home page. After this, click on Choose your Facebook information and then go to view under the Access your information heading. Then click Personal Information and then your contact information. Click on the phone number and click Remove when asked to confirm.
For removing two-factor authentication, you firstly need to disable it. For that on your mobile go to Settings than security and Login and go to Two-factor Authentication. After disabling it you can use an authenticator app rather than the phone number.