This is the 1546th most frequent Chinese word.
二十
"Twenty"
二十 is used here as a numeral to indicate the quantity of books.
我有二十本书。
I have twenty books.
二十 is used here to represent a duration of time, in minutes.
我们需要二十分钟才能到达目的地。
We need twenty minutes to reach the destination.
二十 denotes the age of a person in years in this context.