The minimum distance of the duals of binary irreducible cyclic codes

Irreducible cyclic codes have been an interesting subject of study for many years. The weight distribution of some of them have been determined. We determine the minimum distance and certain weights of the duals of binary irreducible cyclic codes. We show that the weight distribution of these codes is determined by the cyclotomic numbers of certain order. As a byproduct, we describe a class of double-error correcting codes.