9991841 has 6 divisors (see below), whose sum is σ = 10126242. Its totient is φ = 9859200.

The previous prime is 9991837. The next prime is 9991847. The reversal of 9991841 is 1481999.

It can be written as a sum of positive squares in only one way, i.e., 9985600 + 6241 = 3160^2 + 79^2 .

It is not a de Polignac number, because 9991841 - 2² = 9991837 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9991847) 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 5 ways as a sum of consecutive naturals, for example, 5441 + ... + 7041.

It is an arithmetic number, because the mean of its divisors is an integer number (1687707).

Almost surely, 2^9991841 is an apocalyptic number.

It is an amenable number.

9991841 is a deficient number, since it is larger than the sum of its proper divisors (134401).

9991841 is an equidigital number, since it uses as much as digits as its factorization.

9991841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1759 (or 1680 counting only the distinct ones).

The product of its digits is 23328, while the sum is 41.

The square root of 9991841 is about 3160.9873457513. The cubic root of 9991841 is about 215.3848596184.

The spelling of 9991841 in words is "nine million, nine hundred ninety-one thousand, eight hundred forty-one".