111111111091 has 2 divisors, whose sum is σ = 111111111092. Its totient is φ = 111111111090.

The previous prime is 111111111049. The next prime is 111111111101. The reversal of 111111111091 is 190111111111.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 111111111091 - 2¹³ = 111111102899 is a prime.

It is not a weakly prime, because it can be changed into another prime (111111141091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555555545 + 55555555546.

It is an arithmetic number, because the mean of its divisors is an integer number (55555555546).

Almost surely, 2^111111111091 is an apocalyptic number.

111111111091 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111111091 is an equidigital number, since it uses as much as digits as its factorization.

111111111091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9, while the sum is 19.

The spelling of 111111111091 in words is "one hundred eleven billion, one hundred eleven million, one hundred eleven thousand, ninety-one".