Step 1 :
Divide $ 1729245 $ by $ 142736 $ and get the remainder

$$ 1729245 : 142736 = 12 \text{ ( remainder is } \color{blue}{ 16413 } \text{ ) } $$

The remainder is positive ($ 16413 > 0 $), so we will continue with division.

Step 2 :
Divide $ 142736 $ by $ \color{blue}{ 16413 } $ and get the remainder

$$ 142736 : 16413 = 8 \text{ ( remainder is } \color{blue}{ 11432 } \text{ ) } $$

The remainder is still positive ($ 11432 > 0 $), so we will continue with division.

Step 3 :
Divide $ 16413 $ by $ \color{blue}{ 11432 } $ and get the remainder

$$ 16413 : 11432 = 1 \text{ ( remainder is } \color{blue}{ 4981 } \text{ ) } $$

The remainder is still positive ($ 4981 > 0 $), so we will continue with division.

Step 4 :
Divide $ 11432 $ by $ \color{blue}{ 4981 } $ and get the remainder

$$ 11432 : 4981 = 2 \text{ ( remainder is } \color{blue}{ 1470 } \text{ ) } $$

The remainder is still positive ($ 1470 > 0 $), so we will continue with division.

Step 5 :
Divide $ 4981 $ by $ \color{blue}{ 1470 } $ and get the remainder

$$ 4981 : 1470 = 3 \text{ ( remainder is } \color{blue}{ 571 } \text{ ) } $$

The remainder is still positive ($ 571 > 0 $), so we will continue with division.

Step 6 :
Divide $ 1470 $ by $ \color{blue}{ 571 } $ and get the remainder

$$ 1470 : 571 = 2 \text{ ( remainder is } \color{blue}{ 328 } \text{ ) } $$

The remainder is still positive ($ 328 > 0 $), so we will continue with division.

Step 7 :
Divide $ 571 $ by $ \color{blue}{ 328 } $ and get the remainder

$$ 571 : 328 = 1 \text{ ( remainder is } \color{blue}{ 243 } \text{ ) } $$

The remainder is still positive ($ 243 > 0 $), so we will continue with division.

Step 8 :
Divide $ 328 $ by $ \color{blue}{ 243 } $ and get the remainder

$$ 328 : 243 = 1 \text{ ( remainder is } \color{blue}{ 85 } \text{ ) } $$

The remainder is still positive ($ 85 > 0 $), so we will continue with division.

Step 9 :
Divide $ 243 $ by $ \color{blue}{ 85 } $ and get the remainder

$$ 243 : 85 = 2 \text{ ( remainder is } \color{blue}{ 73 } \text{ ) } $$

The remainder is still positive ($ 73 > 0 $), so we will continue with division.

Step 10 :
Divide $ 85 $ by $ \color{blue}{ 73 } $ and get the remainder

$$ 85 : 73 = 1 \text{ ( remainder is } \color{blue}{ 12 } \text{ ) } $$

The remainder is still positive ($ 12 > 0 $), so we will continue with division.

Step 11 :
Divide $ 73 $ by $ \color{blue}{ 12 } $ and get the remainder

$$ 73 : 12 = 6 \text{ ( remainder is } \color{blue}{ 1 } \text{ ) } $$

The remainder is still positive ($ 1 > 0 $), so we will continue with division.

Step 12 :
Divide $ 12 $ by $ \color{blue}{ 1 } $ and get the remainder

$$ 12 : \color{blue}{ \boxed { 1 }} = 12 \text{ ( remainder is } \color{blue}{ 0 } \text{ ) } $$

The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 1 }} $.

This solution can be visualized using a Venn diagram.

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

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