Different phone number for iMessage
I have an iPhone 5 and I'm trying to use iMessage. In Settings>iMessage>Send & Receive, I see the email that is linked to my Apple ID but the number is a totally different one. The phone was passed down through family members but that number is unfamiliar to them. The phone number that I have is already registered to my Apple ID but it is not changing
Can anyone help?
iPhone 5s, iOS 8.4