9789891 has 4 divisors (see below), whose sum is σ = 13053192. Its totient is φ = 6526592.

The previous prime is 9789887. The next prime is 9789937. The reversal of 9789891 is 1989879.

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 9789891 - 2² = 9789887 is a prime.

9789891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (9789851) 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, 1631646 + ... + 1631651.

It is an arithmetic number, because the mean of its divisors is an integer number (3263298).

Almost surely, 2^9789891 is an apocalyptic number.

9789891 is a deficient number, since it is larger than the sum of its proper divisors (3263301).

9789891 is a wasteful number, since it uses less digits than its factorization.

9789891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3263300.

The product of its digits is 326592, while the sum is 51.

The square root of 9789891 is about 3128.8801511084. The cubic root of 9789891 is about 213.9238891419.

The spelling of 9789891 in words is "nine million, seven hundred eighty-nine thousand, eight hundred ninety-one".