989898989 is nontrivially palindromic in base 10.
989898989 is an esthetic number in base 10, because in such base it adjacent digits differ by 1.
It is a weak prime.
It is a palprime.
It is a cyclic number.
It is a Chen prime.
It is an alternating number because its digits alternate between odd and even.
989898989 is an undulating number in base 10.
It is a congruent number.
Almost surely, 2989898989 is an apocalyptic number.
It is an amenable number.
989898989 is an equidigital number, since it uses as much as digits as its factorization.
989898989 is an evil number, because the sum of its binary digits is even.
The square root of 989898989 is about 31462.6602339980. The cubic root of 989898989 is about 996.6215955701.
The spelling of 989898989 in words is "nine hundred eighty-nine million, eight hundred ninety-eight thousand, nine hundred eighty-nine".