This is the 219th most frequent Finnish word.
miljoonan
"Miljoonan" means "of a million" or "million's" in English, indicating possession or relation to a million.
In this sentence, 'miljoonan' is used in the partitive case to indicate an indefinite quantity.
Hän löysi miljoonan syytä olla onnellinen.
They found a million reasons to be happy.
Here, 'miljoonan' is in the genitive case to show possession or association with the euro amount.
Miljoonan euron voitto teki hänestä rikkaan.
A million-euro win made them rich.
In this context, 'miljoonan' describes the size of the population, also in the genitive case to indicate a characteristic of the city.