55 fiveYou could also express 555 as a mixed fraction: 11 05; If you look at the mixed fraction 11 05, you'll see that the numerator is the same as the remainder (0), the denominator is our orinal55 is a square pyramidal number. 55 is: . the 10th Fibonacci number [1] and the 10th triangular number, [2] The sum of 55's dits is also 10.; the 5th heptagonal number, [3] the 5th square