In chemistry, the symbol 11 stands for the element sulfur. The atomic number 11 is 11. The sum of all the other numbers after it is 11 is greater than zero. The number eleven is often used as a symbol for science, or just for luck. In some cultures, if you were born on or before the month of October, you would receive a card with a picture of a golden seal on it, which has been interpreted as being a symbol of prosperity.