This beauty is called Coryphantha elephantidens.
Unfortunately it's not mine.
This cactus belongs to my friend's neighbor.
This neighbor's house is across the street, so I went to take some photos, as her pots of cacti and other flowers were standing outside, at the entrance to her yard.
A few minutes later, this neighbor came out (probably saw me through the window) and started a conversation with me.
As a result, she gave me a baby from her Coryphantha elephantidens, and later I brought her a Gymnocalycium mihanovichii cactus.
And we were both happy!
The photos I were taken with a Lenovo TAB 2 A10-70L tablet
And these succulents are also hers.