They live naturally in groups, so keep a few. They’re very peaceful and don’t hide as such, so I wouldn’t keep them with anything aggressive or territorial. I’ve kept them with dollars in the past, and medium barbs which to be fair were a bit too active for them.
You’ll need a big tank though, since they get to 18”+ and they don’t bend. I had them in a 6x2x2 which became too small for them.