91111111011 has 10 divisors (see below), whose sum is σ = 136104252372. Its totient is φ = 60740740620.

The previous prime is 91111111009. The next prime is 91111111067. The reversal of 91111111011 is 11011111119.

It is not a de Polignac number, because 91111111011 - 2¹ = 91111111009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91111111001) 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 in 9 ways as a sum of consecutive naturals, for example, 562414185 + ... + 562414346.

Almost surely, 2^91111111011 is an apocalyptic number.

91111111011 is a deficient number, since it is larger than the sum of its proper divisors (44993141361).

91111111011 is a wasteful number, since it uses less digits than its factorization.

91111111011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124828543 (or 1124828534 counting only the distinct ones).

The product of its (nonzero) digits is 9, while the sum is 18.

The spelling of 91111111011 in words is "ninety-one billion, one hundred eleven million, one hundred eleven thousand, eleven".