111391 has 4 divisors (see below), whose sum is σ = 127312. Its totient is φ = 95472.

The previous prime is 111373. The next prime is 111409. The reversal of 111391 is 193111.

It is a happy number.

111391 is an esthetic number in base 11 and base 12, because in such bases its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193111 = 29 ⋅6659.

It is an interprime number because it is at equal distance from previous prime (111373) and next prime (111409).

It is a cyclic number.

It is not a de Polignac number, because 111391 - 2⁷ = 111263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111301) 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, 7950 + ... + 7963.

It is an arithmetic number, because the mean of its divisors is an integer number (31828).

2¹¹¹³⁹¹ is an apocalyptic number.

111391 is a deficient number, since it is larger than the sum of its proper divisors (15921).

111391 is an equidigital number, since it uses as much as digits as its factorization.

111391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15920.

The product of its digits is 27, while the sum is 16.

The square root of 111391 is about 333.7529026091. The cubic root of 111391 is about 48.1153187924.

The spelling of 111391 in words is "one hundred eleven thousand, three hundred ninety-one".