"Let me know if you're interested". Is that a statement or a question?

Question

"Let me know if you're interested". Is that a statement or a question?

Answer 1

Statement.  It is stating to tell them if you are interested.  A question needs a question mark.

Answer 2

Actually, it's neither.  It's a command or a request--if you put it in a language that has an imperative mood, like Latin, that's what you would use.  At one time, sentences were classified as declarative (statements), interrogative (questions), imperative (commands or requests), and exclamatory (any of the preceding if they end with exclamation marks).  If you say, "Would you let me know if you're interested?" then it's a question.  Adding "please" doesn't change the nature of the sentence--just makes it more polite, or makes the difference between command and request.

Answer 3

"Let me know if you're interested." is a statement

"Would you let me know if you are interested?" would make it a question.