Here's the entry:
Echinobivia (XEchinobivia 'Rainbow Bursts')
It's an Echinopsis. There was a brief time when XEchinobivia was regarded as a new genus because it was supposed to be a cross between Echinopsis and Lobivia, but now all of the Lobivia species have been reclassified as synonyms of Echinopsis species, so it's just a cross between Echinopsis and Echinopsis.