Yes, you can insert numbering on your map topics by using the Numbering button located in Format Ribbon. You can choose between numbers, letters (lower or upper case) or roman numbers (lower or upper case). The numbering will start from the upper right topic and continue clock-wise.
When a new topic is added, it is automatically numbered. If you want to re-order topics, they will change the numbering accordingly. You can apply numbering to the subtopics as well, which will give outline structure to your map. The numbering will start from the topic you've selected. If the central topic is selected, the numbering will be applied to a whole map. If a topic selected, the numbering will be applied only through its subtopics.