Question 839186
The prime factors of N are 7,7,7,3.  a is the final factor of N.  a may or may not be prime.<P>
The prime factors of 66 are 3, 11. and 2<P>
For N to be a multiple of 66, it must share prime factors with 66.  N has 3 in common with 66, but is missing 2 and 11.  a has to be a multiple of those missing factors.  So a is not prime.  The smallest a is 2*11 = 22.