111001101010991 has 2 divisors, whose sum is σ = 111001101010992. Its totient is φ = 111001101010990.

The previous prime is 111001101010981. The next prime is 111001101010993. The reversal of 111001101010991 is 199010101100111.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111001101010991 is a prime.

Together with 111001101010993, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 111001101010991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111001101010993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55500550505495 + 55500550505496.

It is an arithmetic number, because the mean of its divisors is an integer number (55500550505496).

Almost surely, 2^{111001101010991} is an apocalyptic number.

111001101010991 is a deficient number, since it is larger than the sum of its proper divisors (1).

111001101010991 is an equidigital number, since it uses as much as digits as its factorization.

111001101010991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81, while the sum is 26.

The spelling of 111001101010991 in words is "one hundred eleven trillion, one billion, one hundred one million, ten thousand, nine hundred ninety-one".