Maybe. Even with `double`

, overflow is reached at N==170.

Another problem with `double`

is that the result is
only an approximation to the exact value.
`double`

s have the equivalent of about 15 decimal digits
of accuracy. This might not be good enough.

Here is a Javascript version of the factorial calculator:

Try some values for N that test the boundaries: -1, 0, 20. Then try some small values like 6 or 12.

If you drop a brick from a tower, what happens?