So much for getting some sleep...

According to the standards, conforming shells must use signed long int (or something else that provides the same results when working with values in the range of a signed long int). With the bash being talked about on this thread:

Code:

bash-3.2$ getconf LONG_MAX
9223372036854775807
bash-3.2$ test 9223372030926249001 -eq 9223372030926249000
bash-3.2$ echo $?
1
bash-3.2$ test 9223372030926249001 -eq 9223372030926249001
bash-3.2$ echo $?
0
bash-3.2$ test 9223372030926249001 -eq 92233720309262490009
bash: test: 92233720309262490009: integer expression expected
bash-3.2$

shows the results required for a conforming shell in the 1st two examples and shows an allowed (and expected) result for the 3rd case where the last operand is out of the range of a long int (signed or unsigned).

I agree that it is hard to count the digits when looking at numbers that big, but the shell doesn't allow thousands separators in integer constants given to it in expressions nor when they are used as operands for shell built-ins expecting integer arguments.