The number "999" is a three-digit integer that follows 998 and precedes 1000. It is often recognized as a significant number in various contexts, such as mathematics and emergency services. In many countries, dialing 999 connects callers to emergency services, including police, fire, and medical assistance. In mathematics, 999 can be expressed as the sum of three consecutive integers: 333 + 334 + 335. It is also notable for being a repdigit, meaning all its digits are the same. Additionally, in Roman numerals, 999 is represented as CMXCIX.