9887891 has 4 divisors (see below), whose sum is σ = 10648512. Its totient is φ = 9127272.

The previous prime is 9887887. The next prime is 9887909. The reversal of 9887891 is 1987889.

It is a happy number.

9887891 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9887891 - 2² = 9887887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9887831) 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, 380291 + ... + 380316.

It is an arithmetic number, because the mean of its divisors is an integer number (2662128).

Almost surely, 2^9887891 is an apocalyptic number.

9887891 is a deficient number, since it is larger than the sum of its proper divisors (760621).

9887891 is a wasteful number, since it uses less digits than its factorization.

9887891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760620.

The product of its digits is 290304, while the sum is 50.

The square root of 9887891 is about 3144.5017093333. The cubic root of 9887891 is about 214.6353364103.

The spelling of 9887891 in words is "nine million, eight hundred eighty-seven thousand, eight hundred ninety-one".