999989 has 4 divisors (see below), whose sum is σ = 1052640. Its totient is φ = 947340.

The previous prime is 999983. The next prime is 1000003. The reversal of 999989 is 989999.

It is a happy number.

999989 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 Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-999989 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 999989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999983) 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, 26297 + ... + 26334.

It is an arithmetic number, because the mean of its divisors is an integer number (263160).

2⁹⁹⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

999989 is a deficient number, since it is larger than the sum of its proper divisors (52651).

999989 is a wasteful number, since it uses less digits than its factorization.

999989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52650.

The product of its digits is 472392, while the sum is 53.

The square root of 999989 is about 999.9944999849. The cubic root of 999989 is about 99.9996333320. Note that the first 3 decimals are identical.

The spelling of 999989 in words is "nine hundred ninety-nine thousand, nine hundred eighty-nine".