9989999999 has 24 divisors (see below), whose sum is σ = 11774458080. Its totient is φ = 8450179584.

The previous prime is 9989999933. The next prime is 9990000001. The reversal of 9989999999 is 9999999899.

It is a happy number.

It is not a de Polignac number, because 9989999999 - 2¹² = 9989995903 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (89).

9989999999 is a modest number, since divided by 99999 gives 99899 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9989999099) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2584142 + ... + 2588004.

It is an arithmetic number, because the mean of its divisors is an integer number (490602420).

Almost surely, 2^9989999999 is an apocalyptic number.

9989999999 is a deficient number, since it is larger than the sum of its proper divisors (1784458081).

9989999999 is a wasteful number, since it uses less digits than its factorization.

9989999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4559 (or 4552 counting only the distinct ones).

The product of its digits is 3099363912, while the sum is 89.

The square root of 9989999999 is about 99949.9874887436. The cubic root of 9989999999 is about 2153.7163055486.

The spelling of 9989999999 in words is "nine billion, nine hundred eighty-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".