Hi Abhiram,
This is the maximum for a numeric field, anything above this value will be truncated (this is 2^31 -1). You may want the following JavaScript in the change event of the field.
var newValue = parseInt(xfa.event.newText, 10);
if (isNaN(newValue) || newValue < -2147483648 || newValue > 2147483647)
{
xfa.event.change = "";
}
If you need larger values your will need use a text field.
Bruce