3.1415926535897932384626433832795028841...It turns out that 31415926535897932384626433832795028841 is prime, but you would need a computer to figure that out. Here is e to 37 decimal places.
2.7182818284590452353602874713526624977...The largest prime number that is a substring of these digits is 828182845904523536028747135266249. Of course, that would be hard to find without a computer. However, if I showed you the first 37 digits after the decimal point of (sqrt(3)-1)^(sqrt(2)-1), then you could easily find the largest prime number in those digits. You could do it in your head. How? What is the largest prime substring of the first 37 digits of (sqrt(3)-1)^(sqrt(2)-1)?