How to find factorial of "i"(iota)

0!=1  1!=1  2!=2  3!=6 ...... n!=1*2*3*...*n

Therefore n! exists if and only if n>=0

Therefore i! does not exist or in other words undefined as clearly 1>i(iota)

I do there is an exixtence of iota factorial because the value of 5 iota factorial is 2.490078-0.7747491iota