\[\frac{\left( 3 \cdot 2^{20} - 7 \cdot 2^{19} \right) \cdot 52}{( - 1)^{7}\left( 13 \cdot 8^{4} \right)^{2}} =\]
\[= \frac{2^{19} \cdot (3 \cdot 2 - 7) \cdot 13 \cdot 4}{( - 1)\left( 13 \cdot \left( 2^{3} \right)^{4} \right)^{2}} =\]
\[= \frac{2^{19} \cdot ( - 1) \cdot 13 \cdot 2^{2}}{( - 1)\left( 13^{2} \cdot 2^{24} \right)} =\]
\[= \frac{1}{13 \cdot 2^{3}} = \frac{1}{104}.\]