The GCD of given numbers is 299.
Step 1 : Find prime factorization of each number.
$$\begin{aligned}16146 =& 2\cdot3\cdot3\cdot3\cdot13\cdot23\\[8pt]299 =& 13\cdot23\\[8pt]\end{aligned}$$(view steps on how to factor 16146 and 299. )
Step 2 : Put a box around factors that are common for all numbers:
$$\begin{aligned}16146 =& 2\cdot3\cdot3\cdot3\cdot\color{blue}{\boxed{13}}\cdot\color{red}{\boxed{23}}\\[8pt]299 =& \color{blue}{\boxed{13}}\cdot\color{red}{\boxed{23}}\\[8pt]\end{aligned}$$Step 3 : Multiply the boxed numbers together:
$$ GCD = 13\cdot23 = 299 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.