1111101991 has 2 divisors, whose sum is σ = 1111101992. Its totient is φ = 1111101990.

The previous prime is 1111101977. The next prime is 1111102049. The reversal of 1111101991 is 1991011111.

It is a weak prime.

It is an emirp because it is prime and its reverse (1991011111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1111101991 - 2⁷ = 1111101863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1111101961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555550995 + 555550996.

It is an arithmetic number, because the mean of its divisors is an integer number (555550996).

Almost surely, 2^1111101991 is an apocalyptic number.

1111101991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111101991 is an equidigital number, since it uses as much as digits as its factorization.

1111101991 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 25.

The square root of 1111101991 is about 33333.1965313859. The cubic root of 1111101991 is about 1035.7413348130.

The spelling of 1111101991 in words is "one billion, one hundred eleven million, one hundred one thousand, nine hundred ninety-one".