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{{Infobox number
| number = 281
| prime = 60th
}}

281 is the [[60 (number)|60]]th prime, [[Twin prime|twin prime]] with 283, Sophie Germain prime, sum of the first fourteen primes, sum of seven consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53), [[Chen prime]], [[Eisenstein prime]] with no imaginary part, centered decagonal number.

281 is the smallest prime ''p'' such that the [[Decimal|decimal]] period length of the [[Multiplicative inverse|reciprocal]] of ''p'' is (''p''−1)/10, i.e. the period length of 1/281 is 28. However, in binary, it has period length 70.

The generalized [[Repunit|repunit]] number <math>\frac{281^p-1}{280}</math> is [[Composite number|composite]] for all prime ''p'' < 60000.

NANP telephone area code 281 is an overlay code serving Houston, Texas, and its environs. 


[[Category:Integers]]

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{{Sourceattribution|281 (number)}}