It Weill depend upon how long and under what circumstances.
Generally, you should have received an email from Smarty after 180 days of inactivity giving you a further 40 days to buy a plan. After the, your sim is deactivated and your number would be recycled after some time (I think it may be a further 6 months, but not certain).
Probably worth a web chat with Support Team to clarify where you stand - they can look at your account.
