The sum of all positive divisors of 242 except 1 and itself is
156
242
342
399
Explanation for correct option:
The prime factors of 242 are
242=2×11×11
Therefore the divisor of 242 are 2,11,2×11,11×11 that is 2,11,22,121,
Therefor the sum of these number is
=2+11+22+121=156
Hence, option A is correct .
Let ‘n’ be the smallest positive integer having exactly 21 positive integer divisors including 1 and the number itself, then the units digit of ‘n’ is___