Why Isn't 1 a Prime Number?
Five characters explain why 1 isn't prime, from a song lyric to the mathematician's 'because the definition is convenient.'
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Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2019-05-02-why-isn-t-1-a-prime-number/ (CC BY-NC 4.0)Transcript
[Title] "Why Isn't 1 a Prime Number?"
Student: "Because the definition says so, and that's sacrosanct."
Linguist: "Because 'prime' means 'first,' and… um, wait…"
Conspiracy Theorist: "Oh, it's prime all right. Can't trust the mainstream texts."
Three Dog Night Fan: "Because it's the loneliest number! Although, as the only even prime, 2 can be as bad as 1. It's the loneliest number since the number 1."
Mathematician: "Because the definition says so, and that's convenient."