\[\boxed{\mathbf{153.}}\]
\[\textbf{а)}\ 4! = 1 \cdot 2 \cdot 3 \cdot 4 = 24.\]
\[Делители\ 4!:\]
\[1,\ 2,\ 3,\ 4,\ 6,\ 8,\ 12,\ 24.\]
\[\textbf{б)}\ 5! = 1 \cdot 2 \cdot 3 \cdot 4 \cdot 5 = 120.\]
\[Делители\ 5!:\]
\[1,\ 2,\ 3,\ 4,\ 5,\ 6,\ 8,\ 10,\ 12,\ 15,\ 20,\ 24,\ \]
\[30,\ 40,\ 60,\ 120.\]