989969989 has 2 divisors, whose sum is σ = 989969990. Its totient is φ = 989969988.

The previous prime is 989969971. The next prime is 989970019.

989969989 is nontrivially palindromic in base 10.

989969989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 835788100 + 154181889 = 28910^2 + 12417^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 989969989 - 2⁷ = 989969861 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989919989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494984994 + 494984995.

It is an arithmetic number, because the mean of its divisors is an integer number (494984995).

Almost surely, 2^989969989 is an apocalyptic number.

It is an amenable number.

989969989 is a deficient number, since it is larger than the sum of its proper divisors (1).

989969989 is an equidigital number, since it uses as much as digits as its factorization.

989969989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204073344, while the sum is 76.

The square root of 989969989 is about 31463.7885353941. The cubic root of 989969989 is about 996.6454223923.

The spelling of 989969989 in words is "nine hundred eighty-nine million, nine hundred sixty-nine thousand, nine hundred eighty-nine".