78607 - 1997 + 904(2081-1978)
= 47346 - 1823 + 904(103)
= 47346 - 1823 + 93312
= 47346 + 93312 - 1823
= 141835 - 1823
= 140011

Therefore, the result of the expression 78607 - 1997 + 904*(2081-1978) is 140011.