This is the 848th most frequent German word.
übrigens
By the way.
Used as an introductory comment to provide additional information.
Übrigens, das Konzert beginnt erst um acht.
By the way, the concert starts at eight.
Used to interject an additional, slightly tangential remark about the cake.
Der Kuchen war übrigens sehr lecker.
The cake was, by the way, very delicious.
Used to bring up a new, somewhat related topic during a conversation.