This number is a composite.
Let this number be C. This is the smallest number that can be written as 2a^2 or as 3b^3, for which C+1 and C-1 are both prime. [Hartley]
Let this number be C. This is the smallest number that can be written as 2a^2 or as 3b^3, for which C+1 and C-1 are both prime. [Hartley]