13. In daily life, decimal is often used to represent numbers, using 10 digits: $0,1,2,3,4,5,6,7,8,9$. In electronic computers, binary is used, which only requires two digits: 0 and 1. Just as in decimal addition, "carry over when reaching ten," in binary, "carry over when reaching 2." Thus, we can obtain the following table comparing the decimal and binary representations of natural numbers:
\begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|}
\hline Decimal & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & $\cdots$ \\
\hline Binary & 0 & 1 & 10 & 11 & 100 & 101 & 110 & 111 & 1000 & $\cdots$ \\
\hline
\end{tabular}

The decimal 0 is still 0 in binary, the decimal 1 is still 1 in binary, the decimal 2 becomes $1+1=10$ in binary, the decimal 3 becomes $10+1=11$, and so on. Knowing that the product of ten 2s in decimal is 1024, i.e., $2^{10}=1024$, in binary it is 10000000000. So, what is the decimal representation of the binary number 10110? $\qquad$
$22$