987581 has 16 divisors (see below), whose sum is σ = 1229184. Its totient is φ = 774144.

The previous prime is 987559. The next prime is 987587. The reversal of 987581 is 185789.

It is not a de Polignac number, because 987581 - 2¹⁴ = 971197 is a prime.

It is a super-2 number, since 2×987581² = 1950632463122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987587) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5021 + ... + 5213.

It is an arithmetic number, because the mean of its divisors is an integer number (76824).

2⁹⁸⁷⁵⁸¹ is an apocalyptic number.

It is an amenable number.

987581 is a deficient number, since it is larger than the sum of its proper divisors (241603).

987581 is a wasteful number, since it uses less digits than its factorization.

987581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260.

The product of its digits is 20160, while the sum is 38.

The square root of 987581 is about 993.7711004049. The cubic root of 987581 is about 99.5843077271.

The spelling of 987581 in words is "nine hundred eighty-seven thousand, five hundred eighty-one".