When a candidate updates or deletes their application before the application deadline expires, the number assigned to the candidate disappears from the list.
Once a number has been used, it is consumed, which means that if candidate number 5 deletes their application, the next application that comes in will be assigned number 6, and so on.
Therefore, number 5 disappears completely from the list. Even if a candidate only updates their application, they will receive a new number when it is submitted as a 'new' application.
You can see all actions in the Vacancy Log in the upper right corner of your screen.