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Treebeard's Stumper Answer
10 Jan 97

1997 promises to be a PRIME new year, since 1997 is the 302nd prime number (divisible only by 1 and itself), and:

          -       1997            (prime)
          1        997            (a unit and a prime) *
          19        97            (two more primes
          199        7            (two more primes)
          1997       -            (still prime)

So, when is the NEXT year with this property?

* Technically 1 isn't prime, but it's close enough! Consider this two primes for the stumper.


1997 will be a prime year because 1997 is a prime number, and so are all it's parts, 19, 199, 997, etc. This pattern won't happen again until the year 3137. Is this an omen? The last such year was 1373, when the world was in turmoil. Then again, what about next year 1998? (Just divide by 3...) I think the real lesson is that all numbers are interesting!

I can prove this: Assume there are non-interesting numbers. So there must be a smallest non-interesting number. But that's interesting! Therefore the assumption is false.

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last modified .

Marc Kummel / mkummel@rain.org