13
This number is a prime.
Just showing those entries submitted by 'Harrison': (Click here to show all)
sod(M14 exponent) = sod(M17 exponent) = sod(M18 exponent) = sod(M20 exponent) = 13. [Harrison]
The Gregorian Calendar is named after Pope Gregory XIII. [Harrison]
(There are 6 curios for this number that have not yet been approved by an editor.)
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