Word for Excel column numbering system

In Excel, we have a number set for the columns as such:

A , B , C, ..., Z, AA, ...

Is there a name for this "numbering" set? Such as hexadecimal for base-16, or binary for base-2? Or just natural numbers for base-10

Solution 1:

Apparently it's called the bijective base-26 system. It is a base-26 numeral system where the 26 letters of alphabet are used as the symbols for values 1-26 (there is no zero in this system).

AFAICT, the bijective qualifier indicates that no leading/trailing zeros are permitted or possible.

If you're looking for the equivalent of binary, decimal, hexadecimal etc. for base-26, it would be hexavigesimal.