diff --git a/lua/entities/gmod_wire_expression2/core/number.lua b/lua/entities/gmod_wire_expression2/core/number.lua
index eff2e312..82aee7c3 100644
--- a/lua/entities/gmod_wire_expression2/core/number.lua
+++ b/lua/entities/gmod_wire_expression2/core/number.lua
@@ -303,6 +303,18 @@ end
 
 --[[************************************************************************]]--
 
+__e2setcost(10)
+
+[nodiscard]
+e2function number factorial(number n)
+	if n < 0 then return 0 / 0 end
+	if n > 170 then return math.huge end
+
+	local res = 1
+	for i = 2, n do res = res * i end
+	return res
+end
+
 __e2setcost(2) -- approximation
 
 [nodiscard]
diff --git a/lua/wire/client/e2descriptions.lua b/lua/wire/client/e2descriptions.lua
index d0093edf..d2a153fd 100644
--- a/lua/wire/client/e2descriptions.lua
+++ b/lua/wire/client/e2descriptions.lua
@@ -54,6 +54,7 @@ E2Helper.Descriptions["isinf(n)"] = "Returns 1 if given value is a positive infi
 E2Helper.Descriptions["isnan(n)"] = "Returns 1 if given value is not a number (NaN); otherwise 0."
 E2Helper.Descriptions["inf()"] = "Returns a huge constant (infinity)"
 E2Helper.Descriptions["mod(nn)"] = "Modulo, returns the Remainder after Argument 1 has been divided by Argument 2. Note \"mod(-1, 3) = -1\""
+E2Helper.Descriptions["factorial(n)"] = "Returns the Factorial of the Argument"
 E2Helper.Descriptions["sqrt(n)"] = "Returns the Square Root of the Argument"
 E2Helper.Descriptions["cbrt(n)"] = "Returns the Cube Root of the Argument"
 E2Helper.Descriptions["root(nn)"] = "Returns the Nth Root of the first Argument"