# How can I calculate Riemann zeta function for large imaginary parts?

I tried to calculate it for some complex number with imaginary part more than 10^19 but it didn't work out.

How did you try it, and in what way did it not "work out"?

I tried to calculate it on Sage Cell Server. I wrote zeta(0.5+40000000000000000000*I) and clicked evaluate, then it said there is overflow.

It seems PARI simply can't handle such a large number. Does anyone have any other ideas?