what is the opposite of factorial For example If I have n120

what is the opposite of factorial. For example, If I have n!=120 . How can I then show algebraically that n=5?

Hint:Im using that with large numbers

Also, is there a way in which I can get the answer by using the calculater ??

Solution

You have to calculate n and you know  n!=120

you could repedely devided dy increasing integers

like you devided by m than next term is (m+1) another one is (m+2) .

n!=(1+m)!

For large no

It is impossible to compute factorials
larger than 20 when using built-in data types.
we can now see that even when using the long long
data type, the maximum factorial we can expect to
compute correctly, is only 20!
Other wise use programming or coding language .

Answer