9988999 has 4 divisors (see below), whose sum is σ = 9995400. Its totient is φ = 9982600.

The previous prime is 9988991. The next prime is 9989027. The reversal of 9988999 is 9998899.

9988999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9998899 = 101 ⋅98999.

It is a cyclic number.

It is not a de Polignac number, because 9988999 - 2³ = 9988991 is a prime.

It is a Duffinian number.

9988999 is a lucky number.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9988991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 849 + ... + 4549.

It is an arithmetic number, because the mean of its divisors is an integer number (2498850).

Almost surely, 2^9988999 is an apocalyptic number.

9988999 is a deficient number, since it is larger than the sum of its proper divisors (6401).

9988999 is a wasteful number, since it uses less digits than its factorization.

9988999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6400.

The product of its digits is 3779136, while the sum is 61.

The square root of 9988999 is about 3160.5377706966. The cubic root of 9988999 is about 215.3644368949.

It can be divided in two parts, 99 and 88999, that added together give a palindrome (89098).

The spelling of 9988999 in words is "nine million, nine hundred eighty-eight thousand, nine hundred ninety-nine".