989888989 has 4 divisors (see below), whose sum is σ = 990495324. Its totient is φ = 989282656.

The previous prime is 989888969. The next prime is 989889007.

It is a happy number.

989888989 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 265364100 + 724524889 = 16290^2 + 26917^2 .

It is a cyclic number.

It is not a de Polignac number, because 989888989 - 2⁹ = 989888477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989888909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 300712 + ... + 303985.

It is an arithmetic number, because the mean of its divisors is an integer number (247623831).

Almost surely, 2^989888989 is an apocalyptic number.

It is an amenable number.

989888989 is a deficient number, since it is larger than the sum of its proper divisors (606335).

989888989 is a wasteful number, since it uses less digits than its factorization.

989888989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606334.

The product of its digits is 214990848, while the sum is 76.

The square root of 989888989 is about 31462.5013150576. The cubic root of 989888989 is about 996.6182395881.

The spelling of 989888989 in words is "nine hundred eighty-nine million, eight hundred eighty-eight thousand, nine hundred eighty-nine".