Phone number must accept only numeric values and it should be 10 digits code example
Example: textbox should accept only numbers till 10 digit using angular
<input type="text" name="country_code" title="Error Message" pattern="[1-9]{1}[0-9]{9}">
<input type="text" name="country_code" title="Error Message" pattern="[1-9]{1}[0-9]{9}">