"Sono parecchi milioni."
In the pre-euro era, we'd say "Non mi posso permettere quella macchina" "Già, sono parecchi milioni" ("I can't afford that car" "Yeah, it's several millions"). Nowadays, you'd have to win the lottery to apply that sentence to money. Another possible context would be "I cinesi sono tanti" "Sì, sono parecchi milioni" ("The chinese are many" "Yes, they are several millions").
Duolingo has been very inconsistent with "sono' and 'parecchio' sometimes they accept they are sometimes they onky acceot there are and sometimes it is! Very confusing and whilst i likt thevsite very much the english translations to an emglish speaking person sounds at times awkward !