91111 has 4 divisors (see below), whose sum is σ = 91800. Its totient is φ = 90424.

The previous prime is 91099. The next prime is 91121. The reversal of 91111 is 11119.

91111 is nontrivially palindromic in base 6.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 91111 - 2⁵ = 91079 is a prime.

It is a Duffinian number.

91111 is a modest number, since divided by 111 gives 91 as remainder.

91111 is a lucky number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 91091 and 91100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76 + ... + 433.

It is an arithmetic number, because the mean of its divisors is an integer number (22950).

2⁹¹¹¹¹ is an apocalyptic number.

91111 is a deficient number, since it is larger than the sum of its proper divisors (689).

91111 is a wasteful number, since it uses less digits than its factorization.

91111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688.

The product of its digits is 9, while the sum is 13.

The square root of 91111 is about 301.8459872186. The cubic root of 91111 is about 44.9976953552.

It can be divided in two parts, 91 and 111, that multiplied together give a palindrome (10101).

The spelling of 91111 in words is "ninety-one thousand, one hundred eleven".