987558 has 32 divisors (see below), whose sum is σ = 2322432. Its totient is φ = 276000.

The previous prime is 987541. The next prime is 987559. The reversal of 987558 is 855789.

987558 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987559) by changing a digit.

987558 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 283 + ... + 1433.

It is an arithmetic number, because the mean of its divisors is an integer number (72576).

2⁹⁸⁷⁵⁵⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 987558, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1161216).

987558 is an abundant number, since it is smaller than the sum of its proper divisors (1334874).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

987558 is a wasteful number, since it uses less digits than its factorization.

987558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1180.

The product of its digits is 100800, while the sum is 42.

The square root of 987558 is about 993.7595282562. The cubic root of 987558 is about 99.5835346405.

Subtracting from 987558 its reverse (855789), we obtain a square (131769 = 363²).

The spelling of 987558 in words is "nine hundred eighty-seven thousand, five hundred fifty-eight".