Number Theory
# Prime Numbers

What is the largest even prime number?

*cannot* be written as the sum of 2 prime numbers?

3, 5, and 7 are all prime. Is there an $n > 3$ such that $n,$ $n + 2,$ and $n + 4$ are all prime?

Is there a positive integer $n$ such that $6n + 15$ is prime?