Cactus, variety unknown, in pot

The variety is unknown. After researching, it may be Echinopsis oxygona. This is a pup from an old cactus that was at my parents' house, so it's not a recent variety. It's currently shaped like a light bulb. Rotating the pot occasionally seems to help it maintain its shape.
The pot is a slightly heavy ceramic one from Daiso. The soil is cactus soil from a home improvement center. It was watered thoroughly on 5/23. It is watered thoroughly once a month. It can be displayed immediately upon arrival. The spines are sharp and dangerous to touch. I always touch them when told not to, and the prickles were hard to remove for a while.

Shipping Method
It will be shipped as is in the pot via Raku Raku Mercari便, Takkyubin 60.