Isabela is a province in the Philippines situated in the Cagayan Valley region occupying the northeastern section of Luzon. Its capital is the City of Ilagan.

The province has a land area of 13,102.05 square kilometers or 5,058.73 square miles. Its population as determined by the 2020 Census was 1,697,050. This represented 46.04% of the total population of the Cagayan Valley region, 2.73% of the overall population of the Luzon island group, or 1.56% of the entire population of the Philippines. Based on these figures, the population density is computed at 130 inhabitants per square kilometer or 335 inhabitants per square mile.

-https://www.philatlas.com/luzon/r02/isabela.html