111111110999891 has 2 divisors, whose sum is σ = 111111110999892. Its totient is φ = 111111110999890.

The previous prime is 111111110999873. The next prime is 111111111000023. The reversal of 111111110999891 is 198999011111111.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 111111110999891 - 2⁶ = 111111110999827 is a prime.

It is not a weakly prime, because it can be changed into another prime (111111110999831) 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, 55555555499945 + 55555555499946.

It is an arithmetic number, because the mean of its divisors is an integer number (55555555499946).

Almost surely, 2^{111111110999891} is an apocalyptic number.

111111110999891 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111110999891 is an equidigital number, since it uses as much as digits as its factorization.

111111110999891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 53.

The spelling of 111111110999891 in words is "one hundred eleven trillion, one hundred eleven billion, one hundred ten million, nine hundred ninety-nine thousand, eight hundred ninety-one".