AWK: Discrepancy in numeric output

Shell Programming and Scripting
1

During a file-system cleanup I noticed a strange behavior of awk (HP-UX 11iv3 / IA64). When summing up the size of files in one directory it gives different numbers when using print as opposed to printf:

find . -type f -name '*.dmp.Z' -mtime +35 -exec ls -l {} \+ | \
awk 'BEGIN{ OFMT="%f" } { total += $5 } END{ printf "%d\n", total; print total }'
1439122395
5734089691.000000

However, if I use floating point conversion for printf, the numbers are equal. Is there any (possibly documented) reason for this behavior? For this example I can adjust easily, but it might break older scripts who's coders never were aware of this.

2

I've had trouble in shell with integers equal to or greater than 2147483648 (1024 * 1024 * 1024 * 2).

This is ok.
expr 2147483646 + 1
2147483647

This is wrong!
expr 2147483647 + 1
-2147483648

This is ok.
echo "2147483647 + 1"|bc
2147483648

Your numbers !
expr 5734089690 + 1
1439122395

The limit is mentioned in:
man 5 limits

INT_MAX     2147483647