Step 1 : Find prime factorization of each number.

$$\begin{aligned}28853 =& 11\cdot43\cdot61\\[8pt]684 =& 2\cdot2\cdot3\cdot3\cdot19\\[8pt]28892 =& 2\cdot2\cdot31\cdot233\\[8pt]402 =& 2\cdot3\cdot67\\[8pt]32063 =& 32063\\[8pt]656 =& 2\cdot2\cdot2\cdot2\cdot41\\[8pt]\end{aligned}$$

(view steps on how to factor 28853, 684, 28892, 402, 32063 and 656. )

Step 2 : Put a box around factors that are common for all numbers:

$$\begin{aligned}28853 =& 11\cdot43\cdot61\\[8pt]684 =& 2\cdot2\cdot3\cdot3\cdot19\\[8pt]28892 =& 2\cdot2\cdot31\cdot233\\[8pt]402 =& 2\cdot3\cdot67\\[8pt]32063 =& 32063\\[8pt]656 =& 2\cdot2\cdot2\cdot2\cdot41\\[8pt]\end{aligned}$$

Note that in this example numbers do not have any common factors.

Step 3 : Multiply the boxed numbers together:

Since there is no boxed numbers we conclude that $~\color{blue}{ \text{GCD = 1} } $.

GCD Calculator