99999999

99999999 is the decimal number formed by eight consecutive digits 9. It equals 10^8 − 1 and is the largest eight-digit number in base-10.

In mathematics, 99,999,999 is a composite number. It is divisible by 9 and 11, among other factors. The prime factorization is 3^2 × 11 × 73 × 101 × 137, and equivalently 99 × 1,010,101.

In hexadecimal, 99,999,999 is 0x05F5E0FF. In binary, it is a 27-bit number, lying between 2^26 and 2^27. Its decimal representation is often used in computing and testing as an upper bound for eight-digit integers.