The year 647, as with any year between 601 and 700, fell in the seventh century.
The year 1630 would fall in the 17th Century.
The 21st century.
17th Century
1800 is the last year of the 18th century.
The 13th century started with the year 1201 and finished with the year 1300
No such century existed, as there was no year zero. The century you are probably thinking of ran from 1 to 100. It was the first century AD. Even if there was a year zero, then that would have been an extra year, so it would be 101 years and so it would not be a century.
the 20th century
No such century existed, as there was no year zero. The century you are probably thinking of ran from 1 to 100. It was the first century AD. Even if there was a year zero, then that would have been an extra year, so it would be 101 years and so it would not be a century.
The first year of the fourth century would be 301 (A.D.).
Any year from 1201 to 1900.
This would technically be in the 17th century.
That year would be described as "First Century BC".