What are the factors of 45
\begin{array}{rcrcl} 1&\times&45&=&45\\ 3&\times&15&=&45\\ 5&\times&9&=&45\\ \left{(} 9&\times&5&=&45\\ 15&\times&3&=&45\\ 45&\times&1&=&45 \right{)} \end{array}
The factors of 45 are: 1, 3, 5, 9, 15, 45
1 3 5 9 15 and 45