Alaska is about 1.6 times bigger than Nigeria.

Nigeria is approximately 923,768 sq km, while Alaska is approximately 1,481,348 sq km, making Alaska 60% larger than Nigeria. Meanwhile, the population of Nigeria is ~225.1 million people (224.4 million fewer people live in Alaska).
Tip: This to-scale comparison of Nigeria vs. Alaska uses the Mercator projection, which distorts the size of regions near the poles.