6 ms·

So today is an international prime day because 291113 112913 20131129 are all primes Today could also have been a "perfect prime day" if MM, DD, YY and YYYY ha

So today is an international prime day because 291113 112913 20131129 are all primes Today could also have been a "perfect prime day" if MM, DD, YY and YYYY had been prime (in addition to the above). But it's not the case... 11 -> is prime 29 -> is prime 13 -> is prime 2013 -> not prime (3 x 11 x 61) Too bad! We will have to wait another 16 years before we have a perfect prime day...

ruttiger 13y ago
ya, but each of the factors of 2013 is prime, so that's gotta mean something, right?
- gnur 13y ago
  Isn't always possible to deconstruct the factors of a number in only primes?
  - s-phi-nl 13y ago
    I think ruttiger may mean that 2013 is the product of three unique primes (e.g. 30=2 * 3 * 5 would be another example, but 50=5^2 * 2 is not).
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