PLease help with this problem. My friend and I differ on answer.

(3abc^2 )^4/(7a^2 b)^4 =

3 answers

81c^8/2401a^4.'
There may be a factor for 81 and 2401 but it isn't obvious if there is one.
thank you very much, my friend was right I was wrong
2401 = 7*7*7*7
81 = 3*3*3*3
There are no common factors