Racket Programming. Where am I going wrong?

Question

The question i\'m trying to answer:
The prime factors of 13195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600851475143 ?

Where am I goin

Answer 1

Easy answer:

$ factor 600851475143
600851475143: 71 839 1471 6857

More serious answer: Your prime? function is indeed broken; I'm not even certain what it's trying to do. (Also, your (= n 2) test is too late to be useful: the (even? n) test has trumped it.)

My suggestion: Implement the Sieve of Eratosthenes. Here's my implementation.