Question 841558
2013 = 3*11*61


If none of the elements is 1, there is one set ({3,11,61})


If exactly one of the elements is 1, there are three sets ({3, 11*61}, {11, 3*61}, {61, 3*11}).


If exactly two of the elements are 1, there is one set ({1, 1, 2013}).


# sets = 1+3+1 = 5.