9989899 has 2 divisors, whose sum is σ = 9989900.
Its totient is φ = 9989898.
The previous prime is 9989887. The next prime is 9989921.
It can be divided in two parts, 99 and 89899, that added together give a palindrome (89998).
9989899 is nontrivially palindromic in base 10.
9989899 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.
It is a weak prime.
It is a palprime.
It is a cyclic number.
It is not a de Polignac number, because 9989899 - 211 = 9987851 is a prime.
It is not a weakly prime, because it can be changed into another prime (9989849) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4994949 + 4994950.
It is an arithmetic number, because the mean of its divisors is an integer number (4994950).
Almost surely, 29989899 is an apocalyptic number.
9989899 is a deficient number, since it is larger than the sum of its proper divisors (1).
9989899 is an equidigital number, since it uses as much as digits as its factorization.
9989899 is an evil number, because the sum of its binary digits is even.
The product of its digits is 3779136, while the sum is 61.
The square root of 9989899 is about 3160.6801483225.
The cubic root of 9989899 is about 215.3709047493.
The spelling of 9989899 in words is "nine million, nine hundred eighty-nine thousand, eight hundred ninety-nine".