sqrt(2)^1000 = sqrt(2)^(2xx500) = (sqrt(2)^2)^500 = 2^500√21000=√22×500=(√22)500=2500
An approximate value for this would be 10^15010150 since 2^10 = 1024 ~= 1000 = 10^3210=1024≅1000=103
For a little more accuracy, use log_10 2 ~= 0.30103log102≅0.30103
then log_10 (2^500) = 500 log_10 2 ~= 500 xx 0.30103 = 150.515log10(2500)=500log102≅500×0.30103=150.515
So 2^500 ~= 10^150.5152500≅10150.515
Using an arbitrary precision calculator
sqrt(2)^1000 = 2^500√21000=2500
= 327339060789614187001318969682759915221664204604306478
94832913680961337964046745548832700923259041571508866
84127560071009217256545885393053328527589376