989865 has 12 divisors (see below), whose sum is σ = 1715844. Its totient is φ = 527904.

The previous prime is 989839. The next prime is 989869. The reversal of 989865 is 568989.

It can be written as a sum of positive squares in 2 ways, for example, as 501264 + 488601 = 708^2 + 699^2 .

It is not a de Polignac number, because 989865 - 2⁹ = 989353 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 21997 = 989865 / (9 + 8 + 9 + 8 + 6 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 989865.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 989865.

It is not an unprimeable number, because it can be changed into a prime (989869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10954 + ... + 11043.

It is an arithmetic number, because the mean of its divisors is an integer number (142987).

2⁹⁸⁹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

989865 is a deficient number, since it is larger than the sum of its proper divisors (725979).

989865 is a wasteful number, since it uses less digits than its factorization.

989865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22008 (or 22005 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 989865 is about 994.9195947412. The cubic root of 989865 is about 99.6610188831.

The spelling of 989865 in words is "nine hundred eighty-nine thousand, eight hundred sixty-five".