111990911 has 2 divisors, whose sum is σ = 111990912. Its totient is φ = 111990910.

The previous prime is 111990881. The next prime is 111990913. The reversal of 111990911 is 119099111.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111990911 is a prime.

Together with 111990913, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111990913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55995455 + 55995456.

It is an arithmetic number, because the mean of its divisors is an integer number (55995456).

Almost surely, 2^111990911 is an apocalyptic number.

111990911 is a deficient number, since it is larger than the sum of its proper divisors (1).

111990911 is an equidigital number, since it uses as much as digits as its factorization.

111990911 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729, while the sum is 32.

The square root of 111990911 is about 10582.5758206592. The cubic root of 111990911 is about 482.0154133257.

The spelling of 111990911 in words is "one hundred eleven million, nine hundred ninety thousand, nine hundred eleven".