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| | 23 (number) |
 | | Twenty-three is the ninth prime number, the smallest odd prime that is not a twin prime. |
 | | Twenty-three is also the fifth factorial prime, the second Woodall prime, and the second Smarandache-Wellin prime. |
 | | The fifth Sophie Germain prime and the fourth safe prime, 23 is the next to last member of the first Cunningham chain of the first kind to have five terms (2, 5, 11, 23, 47). |
| encycl.opentopia.com /term/23_(number) (1342 words) |
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