Factorial

Any perfect factorial other than 1 would be having 2 as one of its factors because the natural no. after 1 is 2 and due to this, there is only one perfect factorial that is odd and that factorial is 1.

Forget those PERFECT things... $\fbox{1}$ is the one and only odd factorial number... :p

We know that:

$\boxed{n! = n \times (n-1) \times (n-2) \times .... \times 3 \times 2 \times 1}$ .

We also know that:

$\boxed{even \times even = even}$ , and:

$\boxed{odd \times odd = even}$ .

So, we can examine that, in the case of n! for any n where n > 1 (strictly in the set of integers) we are multiplying by an even number at least once, and so the result will be an even number. Hence, the largest factorial that doesn't contain a multiplication by an even number is $\boxed{1}$ .

charmingly simple problem. 2!=2, 3!=3x2=6 and so on.... hence we find that factorial of every number greater than equal to two is divisible by 2... so only odd factorial is 1 ! =1.

Let n be a perfect factorial number. So, n=k! for some natural k. If k>=2, then n is divisible by 2. Hence the only value of k is 1. thus, n=1!=1

A factorial is denoted as $n!$ , while $!$ is the symbol of factorial, and $n!=n\times(n-1)\times(n-2)\times\dots\times1$ .

For example, $3!=3\times2\times1=6$

To let the perfect factorial number be odd , $2$ cannot be the factor of the factorial number(means that the equation $n\times(n-1)\times\dots\times1$ does not inculde $2$ .) Therefore, $n<2$ .The largest whole number less than $2$ is $1$ .

So, the answer $=1!=\boxed{1}$