| Euler Function φ(n),Generalized Euler Function φ2(n) and Pseudo SmarandacheFunction Z(n) play an important part in the field of number theory,and the research onthe solutions to functional equation of Numerial Theory is also regarded as a crucial topicof number theory.In this thesis,the above-mentioned three function equations and theircombinatorial equations are discussed by learning the basic knowledge of number theoryand refers to a large number of literature pairs.The major research findings are asfollows:In the first part,the problem of Positive integer solutions of equation involvingTernary function and Quaternary function is discussed,such as φ(abc)=φ(a)+3φ(b)+5φ(c),φ(xyz)=φ(x)+φ(y)+φ(z)+6,φ(abcd)=φ(a)+φ(b)+2[φ(c)+φ(d)],Andall Positive integer solutions of the equation are given.In the second part,Based on the first part Euler function,the problem of Positive integer solution of equation involving Generalized Euler function φ(xyz)=φ2 (X)+φ2 (y) +φ2(z) is discussed.And all Positive integer solutions (x,y,z)=(1,2,3),(2,1,3), (3,1,2),(3,2,1),(1,3,2),(2,3,1),(1,1,2),(1,2,1),(1,2,2),(2,1,1),(2,1,2),(2,2,1) of the equa- tion are given.In the third part,The Solvability of composition equation of Z(n2)=φ2(n2), Z(n2)=φ2(n),and Z(n2)=φ22(n) are analyzed.The equation Z(n2)=φ2(n)has only the n=1 Positive integer solution n=1.Equation Z(n2)=φ2(n2) and Z(n2)=φ22(n) have no Positive integer solution. |