Yes, you can create as many administrators as you need.  You can control what each administrator can do with permissions.  There are four levels of permissions:
ORGANIZATION level administrators can do everything that the Primary Administrator can do except update information on the Organization Details page.
EVENT DESIGN level administrators can manage, view reports, create new events, modify the design of assigned events, and assign other event administrators to those events.
EVENT REPORTING level administrators can manage and view reports of assigned events.
EVENT MANAGE level administrators can only manage assigned events
To add or edit an administrator, go to Organization and click the Administrators tab.