Documents for QlikView related information.
Example of using number format for 'k', 'm' and 'b' extension
Edited to reflect the idea that Ralf Becher expressed. Thank you for the suggestion!
..but numbers on data point are still w/o factor denote. The only way to handle this properly is an expression like this:
=If(Value > 1E6, Round(Value/1E6, 1) & 'M',
If(Value > 1E3, Round(Value/1E3, 1) & 'k',