Can $406014677132263504491682$ be the sum of two fourth powers? It may be so. Can anyone use Wolfram Mathematica , SAGE , or some computer program, to check whether this number is the sum of two fourth powers ?
The complete factorization of this number is given by : $406014 677132 263504 491682 = 2 × 1459 × 6883 × 21529 × 938976 705857$
You may want to try some program like this in future for testing.
However, I cannot say anything myself about how the program handles precision, etc, with taking $4$th powers and roots of large numbers, but at least you can be sure it's possible if the program returns with a positive (as you can verify it yourself).
https://js.do/
Some quick testing with random examples such as $32$ and $280286069726155265499093303843106=12371235^4+129387197^4$ seem to work, though.