About maximal antichains of gratings divisors of natural numbers

For the natural numbers of aspects p 1 p 2„.p k and p mq kr s, where p,q,r and p., i = 1, n are different primer numbers, maximal quantity of elements in antichains of the set D(n) of different divisors n, partly-ordered regarding divisions (the width w(n) of the set D(n)) estimated in this paper. For the same case w(n) and antichains from w(n) elements are found. These results are applied to the theory of group.