Caution: numbers that feel prime may be divisible by 3
November 08, 2007 [Misc]Caution: numbers that feel prime may be divisible by 3. For example, 51 and 57.
Conversely, numbers that feel divisible by 3 may be prime. For example, 61, 89 and 97.
Nominations for least prime-feeling numbers that actually are prime: 89 and 101.
Nominations for best prime number: 2 and 101.
Both have digits that sum to 2.
Yes, I was trying to count sheep last night.
Comments
Andy Balaam 2007-12-03
Two times a prime does often feel special.
Midge 2007-11-30
A Prime, primes and half a prime
I was thinking this morning about 34 (nearly my birthday) and how it feels like it should be prime! It is midway between the two nearest primes tho, and two times a prime.