Brazil dwarfs Mongolia: about 8,499,400 km² km² against 1,560,428 km² km². At true size Brazil is about 5.4× larger — the whole of Mongolia fits into Brazil roughly 5 times.
Brazil sits in South America, Mongolia in Asia. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 5.4×.
The old map muddied it further: Mercator inflates Brazil about 1× and Mongolia about 2.2×, so on a Mercator-style map this pair appears 2.6× apart instead of the true 5.4×.
Mongolia fits 5× into Brazil.