New Prime Number is too big for Excel

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They’ve discovered a new Prime number but not for Excel.

The GIMPS project has discovered a new prime number – that’s a number that can only be divided by itself and one.

The new arrival is a bouncing bonny number 257,885,161-1 which is 17 million digits long.

Prime numbers aren’t just mathematical curiosities, they are vital for modern encryption systems.

Alas, the new prime is waaaay to big to insert into Excel. 
Update: Even when you put the number into Excel it’s rounded.

Excel 2003 onwards is ‘limited’ to 9.99999999999999307 or 10 followed by 306 zeros minus a tiny bit. The largest value via formula is 1.7976931348623158308

That’s not to diss Excel – the number range is more than enough for most purposes.  For example, the Gross World Product is ‘just’ 80 trillion dollars, well under the maximum number Excel is capable of.

The trivia question is …

What’s the largest prime number that can be used in an Excel worksheet?  

Can anyone figure it out?  Let us know.

Mersenne 607 in Excel image from New Prime Number is too big for Excel at

It could be Mersenne number 607 or 2607-1 which has 183 digits and was discovered in 1952 – see Wikipedia. Mersenne primes are just a subset of all prime numbers so M607 might not be the largest possible prime for Excel.

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