Sjmarf to People Twitter · 1 month agoIt looks so wrongimagemessage-square72fedilinkarrow-up1635arrow-down130
arrow-up1605arrow-down1imageIt looks so wrongSjmarf to People Twitter · 1 month agomessage-square72fedilink
minus-squareElvith Ma'for@feddit.orglinkfedilinkarrow-up22·1 month 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-squaresugar_in_your_tealinkfedilinkarrow-up15·edit-21 month 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.
minus-squareKnock_Knock_Lemmy_In@lemmy.worldlinkfedilinkarrow-up2·1 month agoAlso Ends in 0, but that’s covered by 5 really.
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.