Let S = {14, 15, 16,…. 22}. If N is the number of subsets of S containing two or more 
elements such that sum of the least and greatest elements has odd number of divisors, then:

$(a,b,c)S=\{14,15,16,\mathrm{......},22\}$

Sum of the least and greatest number must be a perfect square i.e.,36
(  number of divisors of their sum is odd.)
i)  $14,\mathrm{......},22\to 2^7=128$
ii)  $15,\mathrm{.......},21\to 2^5=032$
iii)  $16,\mathrm{........},20\to 2^3=008$
iv)  $17,\mathrm{.........},19\to 2^1=\frac{002}{170}$
 $N=170=2\times 5\times 17$