1079

This number is a composite.

Smallest emirpimes for which dropping any digit gives a prime number. 1079 = 13 * 83 is an emirpimes because its reversal 9701 = 89 * 109. Drop the 1 from 1079 to get the prime 79; drop the 0 from 1079 to get the prime 179; drop the 7 from 1079 to get the prime 109; drop the 9 from 1079 to get the prime 107. [Post]