Let $a = 123456789$ and $b = 987654321$.
Then we have the product $(10^9a+a)(10^9b+b)$.
$(10^9a+a)(10^9b+b) = 10^{18}ab + 10^9ab + 10^9ab + ab$
$= ab(10^{18} + 10^9 + 10^9 + 1)$
$= ab(10^{18} + 2 \times 10^9 + 1)$
$ab = 123456789 \times 987654321$
$ab = (123456789)(987654321) = 121932631112635269$
The product is $121932631112635269(10^{18} + 2 \times 10^9 + 1)$
$10^{18}ab = 121932631112635269000000000000000000$
$2 \times 10^9ab = 243865262225270538000000000$
$ab = 121932631112635269$
Therefore, the result is the addition of the three values:
$121932631112635269000000000000000000$
$+ 243865262225270538000000000$
$+ 121932631112635269$
$= 121932631112635269000000000000000000$
$+ 243865262225270538000000000$
$+ 121932631112635269$
$= 121932631112635269000000000000000000$
$+ 243865262225270538000000000$
$+ 121932631112635269$
$= 12195699413888797435269894101$
$a = 123456789$, $b = 987654321$
$a^2 = 152415787501905206$
$b^2 = 975463162232535041$
$ab = 121932631112635269$
$(10^9 a+a)(10^9 b+b) = 10^{18} ab + 10^9 ab + 10^9 ab + ab$
$= ab(10^{18} + 2 \times 10^9 + 1)$
$= 121932631112635269000000000000000000 + 2438652622252705380000000 + 121932631112635269$
$121932631112635269000000000000000000$
$243865262225270538000000000$
$121932631112635269$
$12195699413888797435269894101$

Final Answer: The final answer is $\boxed{121932631112635269121932631112635269}$
