9891000 has 192 divisors, whose sum is σ = 38450880. Its totient is φ = 2246400.

The previous prime is 9890999. The next prime is 9891023. The reversal of 9891000 is 1989.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 62922 + ... + 63078.

It is an arithmetic number, because the mean of its divisors is an integer number (200265).

Almost surely, 2^9891000 is an apocalyptic number.

9891000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9891000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19225440).

9891000 is an abundant number, since it is smaller than the sum of its proper divisors (28559880).

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

9891000 is a wasteful number, since it uses less digits than its factorization.

9891000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 9891000 is about 3144.9960254347. The cubic root of 9891000 is about 214.6578296239.

Adding to 9891000 its reverse (1989), we get a palindrome (9892989).

The spelling of 9891000 in words is "nine million, eight hundred ninety-one thousand".