[R] Modulus Problem

[McGehee, Robert]

R users, I am having a problem with the modulus operator for large
numbers as follows,

a <- 2
n <- 561
## n is the first Carmichael number, so by Fermat's Little Theorem the
below should equal zero.

(a^(n-1) - 1) %% n
[1] 2.193172e+152
## Seems that R and Fermat disagree

## Also,
1000000000000000000 %% 11
[1] -32

This seems like a bug. Should I be avoiding integer math for large
numbers?

Thanks,
Robert

platform i686-pc-linux-gnu
arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    2                
minor    0.1              
year     2004             
month    11               
day      15               
language R