2222

This number is a composite.

2222 = 2¹ + 2² + 2³ + 2⁵ + 2⁷ + 2¹¹. Note that the number of 2s in the equation equals the larger of the prime exponents, which form a prime sequence, with the exception of '1.' [Gevisier]

The smallest number divisible by a 1-digit prime, a 2-digit prime, and a 3-digit prime. [Trotter]