Northern Mariana Islands is about 17 times smaller than French Southern and Antarctic Lands.

French Southern and Antarctic Lands is approximately 7,829 sq km, while Northern Mariana Islands is approximately 464 sq km, making Northern Mariana Islands 5.93% the size of French Southern and Antarctic Lands.
Tip: This to-scale comparison of French Southern and Antarctic Lands vs. Northern Mariana Islands uses the Mercator projection, which distorts the size of regions near the poles.
Compare further: Northern Mariana Islands vs. French Southern and Antarctic Lands