56

This number is a composite.

Just showing those entries submitted by 'Noll': (Click here to show all)

+ Sigma(56) equals the first prime of the form 6n - 1 factorial, 5!. [Noll]

+ 256 - 1 - 56 + 1 is prime. [Noll]

+ The number of products of distinct primes less than or equal to 11 (the only palindromic prime with an even number of digits) which are congruent to -1 mod 11 is 56. [Noll]

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