1111191911209 has 2 divisors, whose sum is σ = 1111191911210. Its totient is φ = 1111191911208.

The previous prime is 1111191911153. The next prime is 1111191911237. The reversal of 1111191911209 is 9021191911111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1076074275600 + 35117635609 = 1037340^2 + 187397^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1111191911209 is a prime.

It is not a weakly prime, because it can be changed into another prime (1111191711209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555595955604 + 555595955605.

It is an arithmetic number, because the mean of its divisors is an integer number (555595955605).

Almost surely, 2^{1111191911209} is an apocalyptic number.

It is an amenable number.

1111191911209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111191911209 is an equidigital number, since it uses as much as digits as its factorization.

1111191911209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 37.

The spelling of 1111191911209 in words is "one trillion, one hundred eleven billion, one hundred ninety-one million, nine hundred eleven thousand, two hundred nine".