Let the number be $\begin{aligned}
& 2 a b, a+b=13 \
& \Rightarrow a, b \in{0,9} \
& \Rightarrow 6 \text { numbers }{(9,4),(8,5) \ldots(4,9)}
\end{aligned}Similarly,for3 a b, a+b=12 \Rightarrow 7numbersFor4 a b, a+b=11 \RightarrowNumbersFor5 a b, a+b=10 \Rightarrow 9numbersFor6 a b, a+b=9 \Rightarrow 10numbersFor7 a b, a+b=8 \Rightarrow 9numbersFor8 a b, a+b=7 \Rightarrow 8numbersFor9 a b, a+b=6 \Rightarrow 7numbers\thereforeTotalways=64$.