System.Random in ViewBag not displaying as string?

All I am trying to do is create a random number in the Controller and pass it to the View. However when I run the application the View only displays 'System.Random' not a generated value.

Here is my controller:

    // GET: /Products/Create
    public ActionResult Create()
    {
        Random randomID = new Random(Guid.NewGuid().GetHashCode());
        randomID.Next(20, 5000);

        ViewBag.random = randomID.ToString();

        ViewData["random"] = randomID.ToString();

        TempData["random"] = randomID.ToString();

        return View();
    }

I tried the ViewBag, ViewData, and TempData and they all display 'System.Random.'

Here is my View:

@model application.Models.Product

@{
    ViewBag.Title = "Create Product";
}


@using (Html.BeginForm()) 
{
    @Html.AntiForgeryToken()

<div class="form-horizontal">
    <hr />
    @Html.ValidationSummary(true)

    <div class="form-group">
        @Html.LabelFor(model => model.Product_ID, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.TextBoxFor(model => model.Product_ID, new { @readonly = "readonly" })

            @Html.TextBox("random", (string)@ViewBag.random, new { @readonly = true })

            @ViewBag.random

            @ViewData["random"]

            @TempData["random"]

            @Html.ValidationMessageFor(model => model.Product_ID)
        </div>
    </div>

I'm sorry the View is a little messy but I tried all the approaches I could find. What am I missing? I really don't want to have the change the Model. I tried Googling this for hours and nothing can solve my problem. Also is this the simplest approach to creating a random ID number for a product? Any help would be appreciated THANK YOU!