Hi Pradeep, Since 2N and 3N have different number of factors, number N must have 2's in it. On factorizing of 28 (14*2, 7*4, 28*1) we can observe that N must be 2^5*3^3. So 6N would be 2^6*3^4 . Hence the number of factors will be 7*5 = 35.