\[\boxed{\mathbf{2.}\mathbf{111}}\]
Пояснение.
Решение.
\[\textbf{а)}\ НОД(13,\ 26) = 13.\]
\[\textbf{б)}\ 8 = 2 \cdot 2 \cdot 2;\ \ 12 = 2 \cdot 2 \cdot 3\]
\[НОД(8,\ 12) = 2 \cdot 2 = 4.\]
\[\textbf{в)}\ 60 = 2 \cdot 2 \cdot 3 \cdot 5;\ \ 75 =\]
\[= 3 \cdot 5 \cdot 5\]
\[НОД(60,\ 75) = 3 \cdot 5 = 15.\]
\[\textbf{г)}\ НОД(64,\ 128) = 64.\]
\[\textbf{д)}\ 3375\ и\ 5625.\ \]