1992

This number is a composite.

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1992 = 8 x 3 x 83. The only other two years in the period 1000 to 1999 to share the structure of "a x b x 'ab'" (where 'ab' is prime and the concatenation of the factors a and b) are 1316 = 4 x 7 x 47 and 1533 = 7 x 3 x 73. [Trotter]

If you separate the digits of 1992 like 199 2, you have two primes. Note that 199 is the largest prime less than 2 hundred. Separation in the middle gives us 19 92, and 19 turned upside down along with 92 reversed are prime. [Trotter]