Hi , all ,

There may be several different challenges here .

> 10^700+7

This is more of an expression than a numeral .

> 11092001 is a prime. As a UK date it tells a story.

Yes , but it fails to comply with ISO 8601 , and is hence

obsolete and confusing , just as e-mail dates often are .

I tend to think of this challenge :

One may be called upon to name a large prime at a social

gathering , prototypically a "cocktail party" .

You may know a large prime , but can you say it ?

A long string of digits can be hard to speak and even

harder to understand , so there is a long-standing and

useful protocol :

911 can be spoken "nine hundred eleven"

( tho nine hundred onety-one would make more sense ) .

When I write below "123" , I mean

"one hundred twenty-three" .

123123456456911 is prime and can be said :

123 trillion 123 billion 456 million 456 thousand 911 .

For the more adventurous :

123123456456789789911 is prime and can be said :

123 quintillion 123 quadrillion

456 trillion 456 billion 789 million 789 thousand 911 .

Cheers ,

Walter

http://upforthecount.com