# initial: 61 bytes
<?$x=$_GET['x'];for($i=1;$i<=$x;$i++)$c+=$x%$i==0?1:0;echo$c;
# 1. Use -r: remove the php Tag (-2)
$x=$_GET['x'];for($i=1;$i<=$x;$i++)$c+=$x%$i==0?1:0;echo$c;
# 2. `$_GET[x]`: The missing quotes will only yield a notice (not displayed) (-2)
$x=$_GET[x];for($i=1;$i<=$x;$i++)$c+=$x%$i==0?1:0;echo$c;
# 3. move the assignment to the first usage (-3)
for($i=1;$i<=$x=$_GET[x];$i++)$c+=$x%$i==0?1:0;echo$c;
# 4. `?1:0` is unnecessary (-4)
for($i=1;$i<=$x=$_GET[x];$i++)$c+=$x%$i==0;echo$c;
# 5. `==0` can be written `<1` (-1)
for($i=1;$i<=$x=$_GET[x];$i++)$c+=$x%$i<1;echo$c;
# 6. golf the loop head (-7)
for(;$i++<$x=$_GET[x];)$c+=$x%$i<1;echo$c;
# final: 42 bytes
 
# no shorter, but I like it:
for(;$i++<$x=$_GET[x];)$x%$i?:$c++;echo$c;
 

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