Let's look at the center of the main body.

100/0.5 = 200

2200 = 1.607*1060

350*1.607*1060 = 5.6245*1062 MPa (562,450,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 MPa)

What the actual fuck. No wonder nobody's been able to kill Leviathan. He gets tougher exponentially, has no normal organs and heals from the inside out - and if you somehow managed to get to his center to break it and stop him healing, you'd have to do something like throw a freaking solar system at it in order to do any damage.