PrimePi[100]

Plot[PrimePi[x],{x,0,3000000},PlotPoints->100,PlotRange->All]

Plot[PrimePi[x]/(x/Log[x]),{x,0,3000000},PlotPoints->100,PlotRange->All]

Plot[{PrimePi[x],x/Log[x]},{x,0,3000000},PlotPoints->100,PlotRange->All]

Plot[{PrimePi[x],LogIntegral[x]},{x,0,3000000},PlotPoints->100,PlotRange->All]

Plot[PrimePi[x]-LogIntegral[x],{x,0,3000000},PlotPoints->100,PlotRange->All]

ComplexPlot3D[Zeta[s],{s,1-I 50,10+I 50},PlotRange->All]

ComplexPlot3D[Zeta[s],{s,-10-I 20,10+I 20}]

ComplexPlot3D[Zeta[s],{s,-10-I 50,10+I 50},PlotRange->All]