9991139 has 2 divisors, whose sum is σ = 9991140. Its totient is φ = 9991138.

The previous prime is 9991133. The next prime is 9991141. The reversal of 9991139 is 9311999.

9991139 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9991139 - 2⁴ = 9991123 is a prime.

It is a Sophie Germain prime.

Together with 9991141, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 9991096 and 9991105.

It is not a weakly prime, because it can be changed into another prime (9991133) 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, 4995569 + 4995570.

It is an arithmetic number, because the mean of its divisors is an integer number (4995570).

Almost surely, 2^9991139 is an apocalyptic number.

9991139 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991139 is an equidigital number, since it uses as much as digits as its factorization.

9991139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19683, while the sum is 41.

The square root of 9991139 is about 3160.8763025465. The cubic root of 9991139 is about 215.3798153790.

The spelling of 9991139 in words is "nine million, nine hundred ninety-one thousand, one hundred thirty-nine".