It had a density of 130 inhabitants per square kilometre or 340 inhabitants per square mile .
The population of Isabela in the 2015 census was 1,593,566 people , making it the most populated province among the five provinces in Cagayan Valley ( Region II ) .
Isabela had a density of 130 inhabitants per square kilometre or 340 inhabitants per square mile .
The population of Isabela in the 2015 census was 1,593,566 people , making it the most populated province among the five provinces in Cagayan Valley ( Region II ) .