Solution. Among the divisors of a funny number, there cannot be a two or a prime d with a remainder of 1 when divided by 3 (otherwise, the prime d+2 would be divisible by 3, implying d=1). Therefore, the divisors can only be threes (and their powers) and at most one prime divisor p≡2(mod3) (if there is another such divisor q, then d=pq≡1(mod3) and d+2, divisible by 3, is not prime). Moreover, the power of three cannot be greater than 4, since otherwise there would be a divisor d=35, for which d+2=245 is not prime.
Can a funny number have the form 3k⋅p for k<5?