9991111111999 has 2 divisors, whose sum is σ = 9991111112000. Its totient is φ = 9991111111998.

The previous prime is 9991111111981. The next prime is 9991111112011.

9991111111999 is nontrivially palindromic in base 10.

It is a strong prime.

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 9991111111999 - 2²⁵ = 9991077557567 is a prime.

It is a zygodrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9991111111909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995555555999 + 4995555556000.

It is an arithmetic number, because the mean of its divisors is an integer number (4995555556000).

Almost surely, 2^{9991111111999} is an apocalyptic number.

9991111111999 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991111111999 is an equidigital number, since it uses as much as digits as its factorization.

9991111111999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 531441, while the sum is 61.

The spelling of 9991111111999 in words is "nine trillion, nine hundred ninety-one billion, one hundred eleven million, one hundred eleven thousand, nine hundred ninety-nine".