111591 has 8 divisors (see below), whose sum is σ = 165360. Its totient is φ = 74376.

The previous prime is 111581. The next prime is 111593. The reversal of 111591 is 195111.

It is not a de Polignac number, because 111591 - 2¹⁰ = 110567 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2040 + ... + 2093.

It is an arithmetic number, because the mean of its divisors is an integer number (20670).

2¹¹¹⁵⁹¹ is an apocalyptic number.

111591 is a deficient number, since it is larger than the sum of its proper divisors (53769).

111591 is an equidigital number, since it uses as much as digits as its factorization.

111591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4142 (or 4136 counting only the distinct ones).

The product of its digits is 45, while the sum is 18.

The square root of 111591 is about 334.0523911006. The cubic root of 111591 is about 48.1440982275.

The spelling of 111591 in words is "one hundred eleven thousand, five hundred ninety-one".