MySQL integer column with string search returns the invalid result
A column declared to be INT is designed to hold a number, but not a "phone number".  It can be in the range of about +/- 2 billion.

For a phone number, use VARCHAR(20) CHARACTER SET ascii; that will probably be long enough (20 characters) to handle country-code, dashes, extension, and other kruft that the user might enter.

If you desire to validate that the number is a "valid" string, do that in your application code before trying to store it.