Why Are We Called Muslims When the Qur'an Mostly Calls Us Believers?

Assalamu alaikum, everyone. I've been pondering something and thought I'd ask here. In the Qur'an, Allah often addresses us as 'Mu'min' or believers, so why do we commonly refer to ourselves as Muslims? It feels like 'believer' is used more frequently, yet the term 'Muslim' is what we usually go by. I'd love to hear your thoughts on this-maybe there's a deeper reason I'm missing. Jazakum Allahu khairan!