\(B=\left(2016-1\right)\left(2016+1\right)=2016^2-1< 2016^2\Rightarrow B< A\)
\(N=\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\)
\(=\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)=\left(2^8-1\right)\left(2^8+1\right)\)
\(=2^{16}-1< 2^{16}\Rightarrow N< M\)