symsum returning a large fraction

I am using the symsum command to obtain a value for the summation of a series. My specific code is

syms g
SUM = symsum(.9^g,g,0,20);

The answer given to me by matlab is 890581010868487640791/100000000000000000000. I can't seem to change the formatting of the value, any help is appreciated!

Answer 1

[Niels]

SUM may be of class sym, try

SUM=double(SUM)

[Andrew Chen]

Thanks, this works!