plotting - Only significands on y-axis

I would like to create plot similiar to this:

where significands are on y-axis, while $ \times 10^{4} $ is above the plot (or could be placed at any place in graph). So far I managed to get only exponent right, using this code:

f[x_] := 100 Exp[x] Sin[20  x];
ymax = 1.5*^4;
ymin = -1.5*^4;
xticks = {#, #} & /@ Range[0, 5, 0.5];
yticks = 
  Map[
    {#, NumberForm[#, {3, 1}, ExponentFunction -> (4 &)]} &, 

    N[FindDivisions[{ymin, ymax}, 6]]];

 Plot[f[x], {x, 0, 5}, 
   PlotRange -> {{0, 5}, {ymin, ymax}}, 
   Frame -> True, 
   FrameTicks -> {{yticks, None}, {xticks, None}}, 
   Axes -> False]

I will be grateful for any help.

Answer

You can use the internal function Charting`ScaledTicks to get the needed ticks:

plot = Plot[
    f[x],
    {x, 0, 5},
    PlotRange->{{0,5}, {-15000,15000}},
    Frame->True,
    FrameTicks->{{Charting`ScaledTicks[{10^4#&, 10^-4#&}],None}, {Automatic,None}}
]

If you want to add $\times 10^{4}$ above the plot, you need to expand the padding. A good way to do this is to use my GraphicsInformation function to obtain this information. Install with:

PacletInstall[
    "GraphicsInformation",
    "Site" -> "http://raw.githubusercontent.com/carlwoll/GraphicsInformation/master"
]

Then, load it:

<

The image padding is then:

pad = "ImagePadding" /. GraphicsInformation[plot]

{{23., 4.}, {17., 6.5}}

So, the final plot looks like:

Show[
    plot,
    Epilog -> Text[Row@{"\[Times] ", Superscript[10, 4]}, Offset[{0, 10}, Scaled[{0, 1}]], {-1, 0}],
    PlotRangeClipping->False,

    ImagePadding -> pad + {{0, 0}, {0, 14}}
]