14

This number is a composite.

The smallest peculiar semiprime, i.e., a number that is the product of two primes whose concatenation (in some order) produce the decimal expansion of e, e.g., 14 = 2*7. The sequence begins 14, 142, 22519844819412565193, 2244375512401258782637904641, 22443755124012587826379047223, 224437551240125878263790473657153479, ... . See the largest known. [Bajpai]