Is it possible to identify by number in android?

Question

Android

Is it possible (is it worth it) to identify (authorize) a user in android by the phone number of the SIM card that is currently in it?
Those. Is it easy to fake it using applications and are there any in the market?
In principle, the application is not military and rather niche, but if a person wants to do harm, is it easy to implement?

Answer 1

Offhand protection - check by sms or call to the specified number. Viber, Hangout, etc. they do just that.

Answer 2

it’s understandable, I just don’t want to mess with sending SMS ... I
wonder how easy it is to fake a number