Find Greatest Common Divisor of 123987456 and 87, using prime factorization.

Step 1 : Find prime factorization of each number.

$$\begin{aligned}123987456 =& 2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot3\cdot3\cdot3\cdot8969\\[8pt]87 =& 3\cdot29\\[8pt]\end{aligned}$$

(view steps on how to factor 123987456 and 87. )

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

$$\begin{aligned}123987456 =& 2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot\color{blue}{\boxed{3}}\cdot3\cdot3\cdot8969\\[8pt]87 =& \color{blue}{\boxed{3}}\cdot29\\[8pt]\end{aligned}$$

Step 3 : Multiply the boxed numbers together:

$$ GCD = 3 $$

This solution can be visualized using a Venn diagram.

The GCD equals the product of the numbers at the intersection.

GCD Calculator