Total Pixels of an Image

I think my formula has the correct math. However I do not know JavaScript of its Math functions or  what type or precision  or how to handle  My resize function always resizes within 800 pixels of 4MP or less Square 1:1 Aspect ration resize exactly to 4MP however  3:2 and 4:3 common camera Aspect Ratio resize hundreds of Pixels less than 4MP and 16:9 aspect ratio image resize 500 pixel over 4MP.

Perhaps if you know Javascript and Photoshop you can fix my code.

/* ==========================================================
// 2019 John J. McAssey (JJMack)
// ======================================================= */
// This script is supplied as is. It is provided as freeware.
// The author accepts no liability for any problems arising from its use.
// enable double-clicking from Mac Finder or Windows Explorer
#target photoshop // this command only works in Photoshop CS2 and higher
// bring application forward for double-click events
app.bringToFront();
// ensure at least one document open
if (!documents.length) alert('There are no documents open.', 'No Document');
else {
        // declare Global variables
        //main(); // at least one document exists proceed
        app.activeDocument.suspendHistory('4MP','main()');
}
///////////////////////////////////////////////////////////////////////////////
//                            main function                                  //
///////////////////////////////////////////////////////////////////////////////
function main() {
        // declare local variables
        var orig_ruler_units = app.preferences.rulerUnits;
        var orig_type_units = app.preferences.typeUnits;
        var orig_display_dialogs = app.displayDialogs;
        app.preferences.rulerUnits = Units.PIXELS;          // Set the ruler units to PIXELS
        app.preferences.typeUnits = TypeUnits.POINTS;   // Set Type units to POINTS
        app.displayDialogs = DialogModes.NO;                // Set Dialogs off
        try { code(); }
        // display error message if something goes wrong
        catch(e) { alert(e + ': on line ' + e.line, 'Script Error', true); }
        // catch(e){$.writeln(e)}
        app.displayDialogs = orig_display_dialogs;          // Reset display dialogs
        app.preferences.typeUnits  = orig_type_units;   // Reset ruler units to original settings
        app.preferences.rulerUnits = orig_ruler_units;  // Reset units to original settings
}
///////////////////////////////////////////////////////////////////////////////
//                           main function end                               //
///////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////
// The real code is embedded into this function so that at any point it can return //
// to the main line function to let it restore users edit environment and end      //
/////////////////////////////////////////////////////////////////////////////////////
function code() {
        if (activeDocument.width.value * activeDocument.height.value >= 4000000)  {
                //alert("Image Size = " + activeDocument.width.value * activeDocument.height.value + " Pixels");
                var resizePercent=(Math.sqrt(4000000/(activeDocument.height.value/activeDocument.width.value)))/activeDocument.width.value;
                activeDocument.resizeImage(activeDocument.width.value*resizePercent, activeDocument.height.value*resizePercent); // user default interpolation
                alert("New Size = " + activeDocument.width.value * activeDocument.height.value + " Pixels");
        }
}
//////////////////////////////////////////////////////////////////////////////////
//                      Helper Functions                                        //
//////////////////////////////////////////////////////////////////////////////////