size for sum variable limitation on awk

Hello

first, truth been told, I'm not even close to be advanced user. I'm posting here because maybe my question is complicated enough to need your expert help

I need to use awk (or nawk - I don't have gawk) to validate some files by computing the total sum for a large numeric variable.
It can be that my OS does not support it or it can be as simply as modify my command

in this forum I found a simpler command, but that can indicates a limitation

/da9$ echo "12345678910 12345678910" | awk '{sum=$1; sum+=$2; print sum}'
2.46914e+10
/da9$ echo "1234567891 1234567891" | awk '{sum=$1; sum+=$2; print sum}'
2.46914e+09
/da9$ echo "123456789 123456789" | awk '{sum=$1; sum+=$2; print sum}'
246913578

/da9$ file `which awk`
/usr/bin/awk: executable (RISC System/6000) or object module
$ uname -s -r -v
AIX 1 6
$ uname -a
AIX blabla 1 6 00C608324C00

can someone help me make this sum or point me any configuration requirements?

in reality, this is the command I want to use (it can be that the inner print is causing the e+ notation, but I've tried printf and got even worse results):

cat a01.txt | nawk -F"\t" '{print $7,$8,$2";"$18}'| sort | nawk -F";" 'BEGIN{var="inicio";soma=0};{if(var!=$1) {if(var!="inicio") {print var,soma ; var=$1 ; soma=$2} else {var=$1;soma=$2}} else {var=$1;soma=soma+$2} };END{printf "\n",var,"%17.2f",soma}'

(output)

CashB Aprovado S-01 1533.44
Compr Aprovado S-01 3.23697e+09

---------- Post updated at 03:11 PM ---------- Previous update was at 02:45 PM ----------

SOLVED!!

credits to my wonderful friend Luiz Germano (who even called me at a Saturday!)

the problem really was the inner print and the solution was to format both variables

cat a01.txt | nawk -F"\t" '{print $7,$8,$2";"$18}'| sort | nawk -F";" 'BEGIN{var="inicio";soma=0};{if(var!=$1) {if(var!="inicio") {printf ("%s %17.2f\n",var,soma) ; var=$1 ; soma=$2} else {var=$1;soma=$2}} else {var=$1;soma=soma+$2} };END{printf "%s %17.2f\n",var,soma}'

you can use this as a sumif on excel - sum one column by the values of another column - sumif with awk

To see the printf formatting check this : Formatted Printing (sed & awk, Second Edition)