What is 20000000000000000000000000000000000000000000 36842674251081892624?

The expression you provided seems to be two large numbers: 20,000,000,000,000,000,000,000,000,000,000,000,000,000 and 36,842,674,251,081,892,624. If you are asking for their sum, it is simply the addition of the two values. However, the first number is significantly larger than the second, making the sum approximately equal to the first number. If you meant something else, please clarify!