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One of my pet hobbies is trying to figure out the least prime prime number and most prime composite numbers under 100. My votes are 61 or 89 for least prime-se
by zellyn 2y ago
One of my pet hobbies is trying to figure out the least prime prime number and most prime composite numbers under 100.
My votes are 61 or 89 for least prime-seeming primes and 87 and --yep-- 57 for more prime-seeming composites.
- xigoi 2y agoI once wrote in a Math Olympiad solution that 87 is prime. Not my brightest moment.
- im3w1l 2y agoI'm gonna vote 91, since it has large divisors that can't be seen at a glance. 57 and 87 fall apart if you remember that 60 and 90 are divisible by 3.
- expensive_news 2y agoI really enjoy this “proof” that the most prime-seeming composite is 91 https://youtu.be/S75VTAGKQpk https://youtu.be/S75VTAGKQpk