99 (number)

In mathematics

• a Kaprekar number
• a lucky number
• a palindromic number
• the ninth repdigit
• the sum of the cubes of three consecutive integers: 99 = 2³ + 3³ + 4³
• the sum of the sums of the divisors of the first 11 positive integers.
• the highest two digit number in decimal.

  In science

• The atomic number of Einsteinium, an actinide.