Alaska is about 1.2 times bigger than Niger.

Niger is approximately 1,267,000 sq km, while Alaska is approximately 1,481,348 sq km, making Alaska 17% larger than Niger. Meanwhile, the population of Niger is ~24.5 million people (23.8 million fewer people live in Alaska).
Tip: This to-scale comparison of Niger vs. Alaska uses the Mercator projection, which distorts the size of regions near the poles.