Navigate to Menu > Contacts > Companies, click Advanced filters in the center of the screen, find the phone number field and paste the number:
Once you hit save, HubSpot will perform the search. If you want to be able to see the State/Region directly, you can add it as a column by click Edit columns:
Let me know if you have any follow-up questions!
Karsten Köhler HubSpot Freelancer | RevOps & CRM Consultant | Community Hall of Famer