27
This number is a composite.
Just showing those entries submitted by 'Silva': (Click here to show all)
27^27 + (2*7)^(2*7) is prime. [Silva]
The sum of all composite digits (4+6+8+9) equals the first odd prime cubed. [Silva]
The reversal of 27 is prime and the reversal of 72 a
semiprime. [Silva]
(There are 2 curios for this number that have not yet been approved by an editor.)
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