9991842 has 16 divisors (see below), whose sum is σ = 22838592. Its totient is φ = 2854800.

The previous prime is 9991837. The next prime is 9991847. The reversal of 9991842 is 2481999.

It is an interprime number because it is at equal distance from previous prime (9991837) and next prime (9991847).

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 237901 = 9991842 / (9 + 9 + 9 + 1 + 8 + 4 + 2).

It is a junction number, because it is equal to n+sod(n) for n = 9991794 and 9991803.

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 7 ways as a sum of consecutive naturals, for example, 118909 + ... + 118992.

It is an arithmetic number, because the mean of its divisors is an integer number (1427412).

Almost surely, 2^9991842 is an apocalyptic number.

9991842 is an abundant number, since it is smaller than the sum of its proper divisors (12846750).

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

9991842 is a wasteful number, since it uses less digits than its factorization.

9991842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237913.

The product of its digits is 46656, while the sum is 42.

The square root of 9991842 is about 3160.9875039297. The cubic root of 9991842 is about 215.3848668037.

The spelling of 9991842 in words is "nine million, nine hundred ninety-one thousand, eight hundred forty-two".