Sorry, your question is a bit confusing.
A Trusted phone number, is just used to send the 2-Factor authentication codes to when logging in to your Apple ID if you don't have access to a trusted Apple device.
Signing out of your iPhone does nothing to the trusted phone number. The trusted phone number remains as part of your Apple ID until your manually change it there.
Did you lose your actual iPhone?
How would was your phone number compromised? What exactly happened to it?
What does that have to do with tracking your iPhone?
If you lost your iPhone, and removed it from your account, then you can no longer track it.