274

This number is a composite.

+ (274 - 2)2 + (274 - 7)7 + (274 - 4)4 is prime. [Opao]

+ The 274th Lucas number plus 274 is prime. [Opao]

+ 4^4*14^14*274^274 + 1 is the largest non-titanic prime, (687-digit), of form 4^4*14^14*274^274*…*a(n-1)^a(n-1)* a(n)^(a(n)+1, where the bases and exponents are composite, a(n) and 4^4*14^14*…* a(n-1)^a(n-1)*a(n)^a(n)+1 are prime, a(n)>a(n-1), and a(n) is minimal. Note that the previous such primes are: a(1) = 4^4+1 = 257 and a(2) = 4^4*14^14+1 = 2844673747342852097. [Loungrides]

(There is one curio for this number that has not yet been approved by an editor.)

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