目的研究方程φ(φ(n))=2^ω(n)的可解性。方法利用初等方法以及Euler函数的性质。结果给出了方程φ(φ(n))=2^ω(n)的所有正整数解。结论确定该方程共有20个正整数解。
Aim To study the solvability of the equation φ (φ(n) ) = 2^ω(n).Methods Using the elementary methods and the properties of the Euler function. Results All positive integer solutions of the equation φ ( φ (n) ) = 2^ω(n) are obtained. Conclusion The equation has 20 positive integer solutions.