Euler's Totient Function Interactive Visualization

① This GeoGebra example interactively demonstrates Euler's totient function φ(n), showing the count of positive integers less than or equal to n that are coprime to n. ② Core mathematical concepts include number theory, prime factorization, coprimality, arithmetic mean, and the integration of geometric elements like equilateral triangles and circumcircles to create a visual link between abstract arithmetic functions and geometry. ③ Construction details: The Textfield command creates an input box; Setup and Calculate objects manage parameters and computations; variables n and phi store the input and result; Inp handles user input; text displays output. The whole setup provides an interactive numerical and graphical feedback loop. ④ Suitable for high school and above, particularly for introductory number theory, discrete mathematics, or cryptography courses, helping learners grasp the definition and computation of Euler's totient function.