a propósito vs "de paso" to say "by the way"?

Question

How do you say "by the way" in Spanish, as in:> By the way, what's your name?> By the way, where do you live now?> By the way, I met Javier the other day ...Google Translate shows  **a propósito** and **de paso**. Is any of the two more formal than the other or are there regional differences?I also saw another question mentioning one possible translation is **por cierto**, but it doesn't mention "*de paso*", so is "*de paso*" really an expression to be used or did Google mis-translate the context?

Answer 1

Por cierto is what I heard a lot in Spain. I've never heard anyone use 'de paso.'