\[\boxed{\mathbf{84}.}\]
\[1)\ 45^{2} - 16^{2} = 2025 - 216 =\]
\[= 1809\]
\[2)\ 5 \cdot 14^{2} = 5 \cdot 196 = 980\]
\[3)\ \left( 3^{4} \cdot 5 - 181 \right)\ :2^{5} =\]
\[= (81 \cdot 5 - 181)\ :32 =\]
\[= (405 - 181)\ :32 =\]
\[= 224\ :32 = 7\]