989898989898989 has 4 divisors (see below), whose sum is σ = 989899162947324. Its totient is φ = 989898816850656.

The previous prime is 989898989898977. The next prime is 989898989899031.

989898989898989 is nontrivially palindromic in base 10.

989898989898989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 763786357789225 + 226112632109764 = 27636685^2 + 15037042^2 .

It is a cyclic number.

It is not a de Polignac number, because 989898989898989 - 2³² = 989894694931693 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

989898989898989 is an undulating number in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989898989898919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77639522 + ... + 89485715.

It is an arithmetic number, because the mean of its divisors is an integer number (247474790736831).

Almost surely, 2^{989898989898989} is an apocalyptic number.

It is an amenable number.

989898989898989 is a deficient number, since it is larger than the sum of its proper divisors (173048335).

989898989898989 is a wasteful number, since it uses less digits than its factorization.

989898989898989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173048334.

The product of its digits is 90275517038592, while the sum is 128.

The spelling of 989898989898989 in words is "nine hundred eighty-nine trillion, eight hundred ninety-eight billion, nine hundred eighty-nine million, eight hundred ninety-eight thousand, nine hundred eighty-nine".