Is the Universe a Ball?

Do we know the universe is a ball? Or like, I could imagine it could be an infinite variety of shapes. Is there some physical reason why we would think that's the most likely case? Because when you talk about the bendiness, I can think, well, that's just maybe a curve. So we don't know that. And it's definitely going to be bumpy on some sort of locus. There are definitely local bumps. But what we're talking about is on very, very large scales.