3 ms·

I think it’s the other way around — tack this number on the back of anything and the result is composite.

• Cogito 6y ago
  Ah of course and that makes far more sense. Adding this prime to the end of a number guarantees a composite. I wonder if that is a property the belongs to primes, or if there are non-trivial composite examples (any number ending in 2 has this property).
  • bodhiandpysics1 6y ago
    You can rephrase that conjecture to say... given any sequence of digits not ending in 2 (or 0), is there a prime number that ends in that sequence. That's an interesting conjecture!
    • bodhiandphysics 6y ago
      Acchhh!!! Brain fart!!!
    • Cogito 6y ago
      yes I like that phrasing. Similarly we can say there is a class of primes that have this property, what other classes of numbers also have this property?