This is the 6697th most frequent Swedish word.
n
The Swedish "n" is an abbreviation for "nummer," meaning "number" in English.
In this case, 'en' is used with a unit of time 'timme', signifying the quantity as one.
Det tar ungefär en timme att köra dit.
It takes about an hour to drive there.
Here, 'en' functions as an indefinite article introducing 'vän', indicating a singular and non-specific friend.
Vi har en vän som bor i Sverige.
We have a friend who lives in Sweden.
The word 'en' is used as an indefinite article, corresponding to 'an' or 'a' in English.