2. If two is a factor, then 868 is not prime, and you need test no more.
868=2x2x7x31
What is the greatest prime you must consider to test whether 868 is prime
3 answers
In general, to test a number N, the greatest prime you need to try is
√N, since if there is a factor greater than √N, the other factor is less than √N, and you will already have tested that prime.
√N, since if there is a factor greater than √N, the other factor is less than √N, and you will already have tested that prime.
868
1 answer