Question 779892
Unclear what "my sum is" means.  If it means to add the individual digits of the solitary number, then 43 would "equal" 7, and is between 40 & 50.  But it fails to meet your requirement of an "even number". 


The only correct number would be a decimal or fraction  (e.g., 41.2) but fractions are never able to be defined even or odd.


No even (whole) number will suffice to meet all the definitions of your question.