Sum all the factors of a certain natural number two by two to get several natural numbers. Among these numbers, the smallest is 4 and the largest is 140. What is this natural number?
把某个自然数的所有因数两两求和，得到若干个自然数，在这些数中，最小的是4，最大的是140，这个自然数是多少？
<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">140 / 4</gadget>
<output>35</output>

<gadget id="calculator">3 / 1</gadget>
<output>3</output>

<gadget id="calculator">35 * 3</gadget>
<output>105</output>

<result>105</result>