This is part of a guest lecture that legendary mathematician, John Conway, gave at UC Berkley in 2012. I thought it was a goofy aside that could be understoo...
Only if you weren’t taught (or were, but too long ago lol) the divisible by 3 rule - if the sum of the digits is divisible by 3, so is the whole number. 5+1=6 therefore 51 is divisible by 3! Bonus division rule - if it was also an even number and therefore divisible by 2, you could deduce that the whole number was divisible by 6.
No it’s 51
Surely it’s 1? Looks prime, and some people will even argue that it is!
Naw, 5 + 1 = 6, 6 is divisible by 3, so 51 is divisible by 3.
I shared this at work recently and nobody cared. 3 6 and 9 are all kinda special.
Only if you weren’t taught (or were, but too long ago lol) the divisible by 3 rule - if the sum of the digits is divisible by 3, so is the whole number. 5+1=6 therefore 51 is divisible by 3! Bonus division rule - if it was also an even number and therefore divisible by 2, you could deduce that the whole number was divisible by 6.
Actually 51/3! Is 8.5
You bastard
!unexpectedfactorial@sopuli.xyz
Actually, 51 is not divisible by 3!
It is divisible by 3
Hilarious.
Agreed. 51 looks prime AF.