Sjmarf to People [email protected] • 2 months agoIt looks so wrongsh.itjust.worksimagemessage-square72fedilinkarrow-up1635arrow-down129
arrow-up1606arrow-down1imageIt looks so wrongsh.itjust.worksSjmarf to People [email protected] • 2 months agomessage-square72fedilink
minus-squareElvith Ma'forlinkfedilink22•2 months agoThe digit sum of 51 is 6, which is divisible by three. So 51 is also divisible by three. It’s not even hard to see that it’s not prime.
minus-square@[email protected]linkfedilink15•edit-22 months agoYup, my personal prime check is: Even? Ends in 5? Digits sum to 3? If it fails all three and it’s not an “obvious” prime (<20), then it’s prime enough for me.
The digit sum of 51 is 6, which is divisible by three. So 51 is also divisible by three. It’s not even hard to see that it’s not prime.
Yup, my personal prime check is:
If it fails all three and it’s not an “obvious” prime (<20), then it’s prime enough for me.
Also
Ends in 0,
but that’s covered by 5 really.
It’s also covered by being even.