How to write 20-digits numbers without Excel automatically messing them up?

Originally Posted by Richard Buttrey

Can't comment on its efficiency or accuracy but there's an add in here http://precisioncalc.com/xlprecision.html which might be of interest.

Thanks but no, I don’t think refining the precision of my experiments is worth buying another software. Going up to 15-digits numbers already gave me a pretty good precision.

Originally Posted by Richard Buttrey

Just as a matter of interest what are the very big numbers you're handling and what sort of arithmetic do you want to perform with them?

Superior highly composite numbers: http://en.wikipedia.org/wiki/Superio...mposite_number