primepi(2^35)

? default(primelimit)
% 2000000000


? primepi(2^35)
cpu time = 18,133 ms, real time = 18,162 ms.
% 1480206279

? primepi(10^11)
cpu time = 4,744 ms, real time = 4,752 ms.
% 4118054813


Q: Why is the bigger value returned faster?


-- Ruud

? prime(1480206279)
cpu time = 18,874 ms, real time = 18,937 ms.
% 34359738337

? prime(4118054813)
cpu time = 4,909 ms, real time = 4,917 ms.
% 99999999977