9991939 has 2 divisors, whose sum is σ = 9991940.
Its totient is φ = 9991938.
The previous prime is 9991879. The next prime is 9991963. The reversal of 9991939 is 9391999.
9991939 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 9991939 - 27 = 9991811 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 9991892 and 9991901.
It is not a weakly prime, because it can be changed into another prime (9991139) 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 as a sum of consecutive naturals, namely, 4995969 + 4995970.
It is an arithmetic number, because the mean of its divisors is an integer number (4995970).
Almost surely, 29991939 is an apocalyptic number.
9991939 is a deficient number, since it is larger than the sum of its proper divisors (1).
9991939 is an equidigital number, since it uses as much as digits as its factorization.
9991939 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 177147, while the sum is 49.
The square root of 9991939 is about 3161.0028471990.
The cubic root of 9991939 is about 215.3855637811.
The spelling of 9991939 in words is "nine million, nine hundred ninety-one thousand, nine hundred thirty-nine".