184

This number is a composite.

184 = 2³ * 23 (concatenation of the first two primes). [Sladcik]

The smallest number that can be written as q * p^q + r * p ^r, where p, q and r are distinct primes (184 = 3 * 2³ + 5 * 2⁵). [Thoms]

2¹⁸⁴ with the last digit removed is prime. [Blevins]