How many 18650 batteries would fit around a 26650 battery?

I'm wondering if somebody that maybe has both a 26650 battery and some 18650 batteries and how many 18650 would surround 1 26650 battery? I have this idea of a copper plate fitting the shape with soldered Beryllium springs...

Hi !

about 7,6 pcs 18650 around the 26650.

if you have some kind of 1mm thick wrap on the 26650 so it becomes 28mm in diameter you would be able to perfectly fit 8 pcs 18650s around it.
atleast derived from simple trigometrics.....

Regards
/Per