There are a few rules to significant figures. The first is that any non-zero digits count as significant figures, so 1, 2 and 8 are significant figures. Now we have 3 significant figures so far.
(significant figure = sigfig = sf)
There are a few cases in which zero can count as a significant figure. If it is between two non-zero digits, like in 405 (3 sig fig) or in 6074 ( 4 sig fig), so the zero between the 2 and the 8 counts as a significant figure, raising the total of significant figures up to four.
Another case is when a zero is added on the end of a decimal, like in the example 2 (1sf) versus 2.0 (2sf) This is essentially the same as 2, but has 0 added on the end, after the decimal. This zero counts as a significant figure. 12080 has no decimal point, so this does not matter in this example.
The total number of significant figures is 4.