989999989 is nontrivially palindromic in base 10.
989999989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a semiprime because it is the product of two primes.
It is a Duffinian number.
It is a congruent number.
Almost surely, 2989999989 is an apocalyptic number.
It is an amenable number.
989999989 is a wasteful number, since it uses less digits than its factorization.
989999989 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 90000010.
The square root of 989999989 is about 31464.2652703031. The cubic root of 989999989 is about 996.6554897213.
The spelling of 989999989 in words is "nine hundred eighty-nine million, nine hundred ninety-nine thousand, nine hundred eighty-nine".