987889 has 6 divisors (see below), whose sum is σ = 1149234. Its totient is φ = 846720.

The previous prime is 987869. The next prime is 987911. The reversal of 987889 is 988789.

It can be written as a sum of positive squares in only one way, i.e., 893025 + 94864 = 945^2 + 308^2 .

It is a de Polignac number, because none of the positive numbers 2^k-987889 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49), and also a Moran number because the ratio is a prime number: 20161 = 987889 / (9 + 8 + 7 + 8 + 8 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (987809) 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 5 ways as a sum of consecutive naturals, for example, 10032 + ... + 10129.

It is an arithmetic number, because the mean of its divisors is an integer number (191539).

2⁹⁸⁷⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

987889 is a deficient number, since it is larger than the sum of its proper divisors (161345).

987889 is a wasteful number, since it uses less digits than its factorization.

987889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20175 (or 20168 counting only the distinct ones).

The product of its digits is 290304, while the sum is 49.

The square root of 987889 is about 993.9260535875. The cubic root of 987889 is about 99.5946592084.

Subtracting 987889 from its reverse (988789), we obtain a square (900 = 30²).

The spelling of 987889 in words is "nine hundred eighty-seven thousand, eight hundred eighty-nine".