Calanasan, officially the Municipality of Calanasan,, is a municipality in the province of Apayao, Philippines. According to the 2020 census, it ha…Calanasan, officially the Municipality of Calanasan,, is a municipality in the province of Apayao, Philippines. According to the 2020 census, it has a population of 12,550 people, making it the least populated municipality in the province.