9991847 has 2 divisors, whose sum is σ = 9991848. Its totient is φ = 9991846.

The previous prime is 9991837. The next prime is 9991879. The reversal of 9991847 is 7481999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9991847 - 2¹⁶ = 9926311 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9991837) by changing a digit.

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 as a sum of consecutive naturals, namely, 4995923 + 4995924.

It is an arithmetic number, because the mean of its divisors is an integer number (4995924).

Almost surely, 2^9991847 is an apocalyptic number.

9991847 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991847 is an equidigital number, since it uses as much as digits as its factorization.

9991847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 47.

The square root of 9991847 is about 3160.9882948217. The cubic root of 9991847 is about 215.3849027305.

The spelling of 9991847 in words is "nine million, nine hundred ninety-one thousand, eight hundred forty-seven".