Prophetstown, IL has a population of 2,093 and is the 10,744th largest city in the United States. The population density is 1,526 per sq mi which is 587% higher than the Illinois average and 1585% higher than the national average. The median age in Prophetstown is 43 which is approximately 15% higher than the Illinois average of 37. In Prophetstown, 53% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 83% of Prophetstown residents were born in Illinois, 15% were born out of state, 1% were born outside of the United States and 1% were foreign born.