192

This number is a composite.

3^192 + 192 - 2 is prime and contains a sum of digits equal to 19^2. [Patterson]

The smallest happy number sandwiched between a twin prime pair. [Gupta]

The only 3-digit compositorial number n, (192 = 4*6*8), such that (n-1, n+1) is a twin prime pair, i.e., (191, 193). [Loungrides]