Is there a formula to find the product of n natural numbers. For example can I determine the value of 19! by the formula.

We know that Lt n -> infinity n!/ {sqrt(2pi*n)(n/e)^n} =
1.

Therefore n! asymptotically behaves like
sqrt((2pi*n)(n/e)^n.

Therefore n! = sqrt((2pi*n)(n/e)^n
approximately. The formula holds better for large
n.

Ex 19! =
2.12*10^17.

19! = 2.11*10^17 using formula.