Probably some sort of Rebutia. Wait until it flowers, the color will help ID

I agree. I used to grow dozens of sp.

Keep them very cold and dry in winter to get the best blooming. Water and feed generously in summer and fall.

Looks to me a little like a Monadenium.

@robinswfl

I can see how you might get that idea, but this is a true cactus.

All of the plants formerly called Monadenium are Euphorbia.