Gah I got my maths wrong it's actually slightly worse cos I didn't notice the currency changes.
$$1,140,900,000,000,000,000,000,000,000,000
plus
£1,000,000,017,600,000,000,000,000
Exchange rate of 1.64705 from quids to bucks
So thats $1,140,901,647,050,028,988,080,000,000,000 or £692,693,995,469,521,991,934,523,998,208
Six hundred and ninety two octillion pounds, sounds much more reasonable.