> I immedieatly thought it was because float64 couldn't cover that number so I told him to use longdouble dtype (it's 80 bits in Intel I think) and the problem

> I immedieatly thought it was because float64 couldn't cover that number so I told him to use longdouble dtype (it's 80 bits in Intel I think) and the problem solved. This is a very dangerous habit. If 64 bits isn't enough you are generally using the wrong representation.