Two millennia is equal to 200 decades.
There are 100
5000000
300 of them
672365
300.
900
The answer depends on 6.5 WHAT! Seconds? Millennia?
1 millennia =1000 year 9 millennia =9000 yrs
1 millennia =1000 year 8 millennia =8000 yrs
1 millennia =1000 year 6 millennia =6000 yrs
1 millennia =1000 year 2 millennia =2000 yrs