987881 has 4 divisors (see below), whose sum is σ = 997764. Its totient is φ = 978000.

The previous prime is 987869. The next prime is 987911. The reversal of 987881 is 188789.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188789 = 71 ⋅2659.

It can be written as a sum of positive squares in 2 ways, for example, as 737881 + 250000 = 859^2 + 500^2 .

It is a cyclic number.

It is not a de Polignac number, because 987881 - 2¹⁰ = 986857 is a prime.

It is a super-2 number, since 2×987881² = 1951817740322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (987821) 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 3 ways as a sum of consecutive naturals, for example, 4790 + ... + 4991.

It is an arithmetic number, because the mean of its divisors is an integer number (249441).

2⁹⁸⁷⁸⁸¹ is an apocalyptic number.

It is an amenable number.

987881 is a deficient number, since it is larger than the sum of its proper divisors (9883).

987881 is a wasteful number, since it uses less digits than its factorization.

987881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9882.

The product of its digits is 32256, while the sum is 41.

The square root of 987881 is about 993.9220291351. The cubic root of 987881 is about 99.5943903659.

It can be divided in two parts, 98788 and 1, that added together give a palindrome (98789).

The spelling of 987881 in words is "nine hundred eighty-seven thousand, eight hundred eighty-one".