I got it by experimentation, and then saw that Arvi had also determined
the same limit. I find it interesting that MS makes no attempt to
explain such an unusual limit.

An additional unusual limit that applies, is that MOD returns #NUM!
regardless of the quotient if the first argument exceeds
2.68873542664192E14 = 2^20+2^19+2^18+2^17+2^15+2^12+2^8+2^6
which is within the range of exact DP representation of whole numbers by
more than an order of magnitude.

Jerry

Dana DeLouis wrote:

Did you get 134217728 from the following Microsoft kb article?

XL: MOD() Function Returns #NUM! Error Value
http://support.microsoft.com/default...b;en-us;119083