91010111111 has 4 divisors (see below), whose sum is σ = 91101396072. Its totient is φ = 90918826152.

The previous prime is 91010111077. The next prime is 91010111161. The reversal of 91010111111 is 11111101019.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91010111111 is a prime.

It is a Duffinian number.

91010111111 is a modest number, since divided by 111111 gives 91010 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 91010111111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91010111161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45640985 + ... + 45642978.

It is an arithmetic number, because the mean of its divisors is an integer number (22775349018).

Almost surely, 2^91010111111 is an apocalyptic number.

91010111111 is a deficient number, since it is larger than the sum of its proper divisors (91284961).

91010111111 is an equidigital number, since it uses as much as digits as its factorization.

91010111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91284960.

The product of its (nonzero) digits is 9, while the sum is 17.

The spelling of 91010111111 in words is "ninety-one billion, ten million, one hundred eleven thousand, one hundred eleven".