JDK 8u144 
========= 
exponent = 500 
time is 0.004838 
total is 21474836470000000 
time is 0.004555 
total is 21474836470000000 
time is 0.001197 
total is 21474836470000000 
time is 0.001257 
total is 21474836470000000 
time is 0.001419 
total is 21474836470000000 
time is 0.001319 
total is 21474836470000000 
time is 0.001270 
total is 21474836470000000 
time is 0.001270 
total is 21474836470000000 
time is 0.001261 
total is 21474836470000000 
time is 0.001262 
total is 21474836470000000 
time is 0.001303 
total is 21474836470000000 

exponent = 800 
time is 0.218941 
total is 21474836470000000 
time is 0.222912 
total is 21474836470000000 
time is 0.032604 
total is 21474836470000000 
time is 0.031032 
total is 21474836470000000 
time is 0.030064 
total is 21474836470000000 
time is 0.042201 
total is 21474836470000000 
time is 0.041038 
total is 21474836470000000 
time is 0.041307 
total is 21474836470000000 
time is 0.042691 
total is 21474836470000000 
time is 0.041285 
total is 21474836470000000 
time is 0.042435 
total is 21474836470000000 

exponent = 1000 
time is 0.281175 
total is 21474836470000000 
time is 0.247480 
total is 21474836470000000 
time is 0.043577 
total is 21474836470000000 
time is 0.041678 
total is 21474836470000000 
time is 0.041574 
total is 21474836470000000 
time is 0.049230 
total is 21474836470000000 
time is 0.050784 
total is 21474836470000000 
time is 0.041619 
total is 21474836470000000 
time is 0.034542 
total is 21474836470000000 
time is 0.029880 
total is 21474836470000000 
time is 0.032231 
total is 21474836470000000