This number is a composite.

+ 255 is the least odd integer greater than 3 which is not the sum of two distinct powers of two and a prime.

+ 255 (3*5*17) is a sphenic number, i.e., the product of three distinct primes. The next sphenic number is 258 (2*3*43). Curiously, 32 + 53 + 1743 is prime. [Honaker]

+ The smallest number n such that 2^99+n is prime. [Loungrides]

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