On the single property page the phone number displayed in the sidebar is a User Phone Number
You can change it in the user settings. There are 2 ways to customize it
1) Visit /wp-admin/ >> Users >> Edit
Please change it here:
Scroll down and click "Update User"
The other way how you can do it:
Please login as a user and visit your /panel/ page. You can click "Edit profile" menu link and change the number
Please click "Update profile" button