11011110991 has 2 divisors, whose sum is σ = 11011110992. Its totient is φ = 11011110990.

The previous prime is 11011110967. The next prime is 11011111009. The reversal of 11011110991 is 19901111011.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11011110991 - 2⁵ = 11011110959 is a prime.

It is a super-2 number, since 2×11011110991² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11011110961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5505555495 + 5505555496.

It is an arithmetic number, because the mean of its divisors is an integer number (5505555496).

Almost surely, 2^11011110991 is an apocalyptic number.

11011110991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11011110991 is an equidigital number, since it uses as much as digits as its factorization.

11011110991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81, while the sum is 25.

The spelling of 11011110991 in words is "eleven billion, eleven million, one hundred ten thousand, nine hundred ninety-one".