Assuming the full stops are thousand separators, the answer is 4 significant digits. However, integers ending in zero are ambiguous.
4
It has two significant digits.
It has 3 significant digits.
3 significant digits.
Five. All nonzero digits are significant and zeros in between significant digits are significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
50.4 has 3 significant digits.
There are 4 significant digits in 5600.
This number has seven significant digits.
There are 5 significant digits in 18.0140.