Question

3^8-1能被哪些正整数整除,为什么?

Answer 1

3^8-1 =(3^4+1)(3^2+1)(3+1)(3-1) =6560=2^5×5×41

可以 被整除的正整数有：,1,2,4,5,8,16,32,10,20,40,80,41,82,1280,164,205,328,656,1312,410,820,1640,3280,6560

共有 （5+1）×（1+1）×（1+1）=24个