Yes, this should be possible, but there is a likely explanation of why you cannot reuse that meeting ID.
Likely when you left the last company, they deactivated your profile, rather than deleting it. This essentially puts that profile on ice and freezes all meetings and other info. While that account and all associated meetings are frozen, those IDs cannot be used by other accounts. This would mean that you would need to request your old company either delete your old profile or to reactivate it and manually change your PMI, either of which would free up your mobile number to be used as your new PMI.
Hope that helps and please make sure to mark the solution as accepted if this information is what you needed.