One way to determine the number is to multiply 2 and 9, this is because the resulting number will be divisible by them perfectly. Let's try:
![2\cdot9=18](https://img.qammunity.org/2023/formulas/mathematics/high-school/dl3d98hf8yjcuz749amra3go8gqapi1tfb.png)
So our candidate is 18, we need to test if it's divisible by 2 and 9 perfectly:
![\begin{gathered} (18)/(2)=9 \\ (18)/(9)=2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/gwbk8bslq679bvonwhlxzv7br6rjlk34w7.png)
It is, therefore the number is 18.