989555989 has 2 divisors, whose sum is σ = 989555990. Its totient is φ = 989555988.

The previous prime is 989555981. The next prime is 989555993.

989555989 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 987027889 + 2528100 = 31417^2 + 1590^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 989555989 - 2³ = 989555981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989555981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494777994 + 494777995.

It is an arithmetic number, because the mean of its divisors is an integer number (494777995).

Almost surely, 2^989555989 is an apocalyptic number.

It is an amenable number.

989555989 is a deficient number, since it is larger than the sum of its proper divisors (1).

989555989 is an equidigital number, since it uses as much as digits as its factorization.

989555989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52488000, while the sum is 67.

The square root of 989555989 is about 31457.2088558410. The cubic root of 989555989 is about 996.5064724780.

The spelling of 989555989 in words is "nine hundred eighty-nine million, five hundred fifty-five thousand, nine hundred eighty-nine".