# I Identify factorial

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1. Jul 5, 2016

### DuckAmuck

Is there a way to identify a factorial without referring to computation of a factorial?

For example, is there a way to identify 5040 as a factorial and a way to identify 5050 as not a factorial?

2. Jul 6, 2016

3. Jul 6, 2016

### micromass

You can check divisibility by $2$, $3$, etc. That is often very easy to do.

Also, check Wilson's theorem.