9989999 has 8 divisors (see below), whose sum is σ = 10634400. Its totient is φ = 9351936.

The previous prime is 9989957. The next prime is 9990017. The reversal of 9989999 is 9999899.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9989999 - 2¹² = 9985903 is a prime.

It is a Duffinian number.

9989999 is a modest number, since divided by 9999 gives 998 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9989699) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1907 + ... + 4859.

It is an arithmetic number, because the mean of its divisors is an integer number (1329300).

Almost surely, 2^9989999 is an apocalyptic number.

9989999 is a deficient number, since it is larger than the sum of its proper divisors (644401).

9989999 is a wasteful number, since it uses less digits than its factorization.

9989999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3169.

The product of its digits is 4251528, while the sum is 62.

The square root of 9989999 is about 3160.6959676628. The cubic root of 9989999 is about 215.3716233758.

The spelling of 9989999 in words is "nine million, nine hundred eighty-nine thousand, nine hundred ninety-nine".