It is known that a=2**2*3**2*5**2, then how many factors of a are there.
已知a=2**2*3**2*5**2，那么a的因数有多少个．
<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">3 * 3 * 3</gadget>
<output>27</output>

<result>27</result>