Harry W. Ritchie is an American mathematician known for his contributions to the field of mathematics, particularly in the areas of number theory and combinatorics. He has published numerous research papers and has been involved in various academic projects throughout his career. In addition to his research, Ritchie has also played a significant role in education, teaching at several universities. His work has influenced both students and fellow mathematicians, helping to advance the understanding of complex mathematical concepts and their applications in real-world scenarios.