A 'Googol' is the large number 10 to the power of 100; that is, the digit 1 followed by 100 zeroes:
10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.