It has 21 zeros, because 'Giga' means 'a Billion'. Thus, one GigaTrillion is 1 Billion-Trillion. A billion has 9 zeros, and a trillion has 12 zeros.
However, if you are referring to the United Kingdom, a billion has 12 zeros and a trillion has 18 zeros, so it would be 30 zeros.
it is in the millions
octillion
sextillion
A number followed by 27 zeros is an octillion. This number is called 9 octillion
it is infinite. the most zeros in a number that we know today would have to be a hundred zeros. that number is called a google.
octillion
it is in the millions
sextillion
Trillion
nonevsextillionocteillion
2*1020 this is called 200quintillion a quintillion is a number with 18 zeros a sextillion is a number with 21 zeros your number has 20 zeros therefore it is not quite a sextillion yet.
A number followed by 27 zeros is an octillion. This number is called 9 octillion
ten's of billions
One billion
Since that is an invented number, it has just as many zeroes as you decide it to have.