For 10 points, identify these numbers that can be used to factor larger numbers and have  no divisors other than 1 and itself.
Its namesake counting function, pi of n, is approximately given by n over the natural  logarithm of n. 1024 bit versions of these are used in Diffie-Hellman key exchange, and its  distribution is linked to the zeros of the Riemann zeta function. The sieve of Erastosthenes is used  to find small ones of these, and there are 47 known Mersenne ones of these. Goldbach's  conjecture states that all even integers greater than 2 can be expressed as sum of two of these  numbers. For 10 points, identify these numbers that can be used to factor larger numbers and have  no divisors other than 1 and itself.
Its namesake counting function, pi of n, is approximately given by n over the natural  logarithm of n. 1024 bit versions of these are used in Diffie-Hellman key exchange, and
{prime} numbers