I don't know metric, but I had that converted to pounds and I got 3lbs. I know that this at gun had to weight more than 3 pounds, so your number is off. Tell us how many men would be needed to move a pak40.
You probably have to erase the dot in the number, so it's 1400 Kilograms which is about 3087 lbs.
You would probably need a lot of men, but in the real war it wasn't movable without a vehicle like a halftrack.
/Edit: Or some tasty horses as ferwiner added.