Hardware cost - 15 Billion USD:To hack bitcoin, or execute a 51% attack, you need to buy enough miners to mach the hash rate of the current mining network - 180 million Terra hash per second.
To do this, you would need roughly 1.5 million S19 miners, costing about $8000 per.
This, plus a warehouse to keep them in, plus power set up etc. would total about 15 Billion USD.
Electricity cost - 10 million USD/day:With a good institutional electricity rate, you would you about 4875 Megawatt per day, costing over 10 million USD.
To put that in perspective, check this out:

I think it's safe to say that Bitcoin is practically unhackable, in the sense of 51% attacks....
Check out the full calculation, and more detailed explanation at:
https://solberginvest.com/blog/blockchain/