How to change the field settings or types For Phone Numbers

I have data that I cannot make a custom type to change the formatting?
I have phone numbers in a table that are being tagged and labeled as currency...
There seems to simple fix for something like this.

How are the phone numbers stored in your database? Surely not in a numeric?

Just have it as
type/Integer or type/Text

Which integer or text? If they're stored as integer, they will be formatted incorrectly. Given that telephone numbers tend to have leading zeroes and/or international '+' formatting, they should be stored as strings (normally varchar).
Modify the view to include an extra column that formats the number as a varchar. You could add extra telephone number formatting to make it pretty too.