111691 has 4 divisors (see below), whose sum is σ = 113584. Its totient is φ = 109800.

The previous prime is 111667. The next prime is 111697. The reversal of 111691 is 196111.

111691 = 9² + 10² + ... + 69².

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

It is not a de Polignac number, because 111691 - 2⁵ = 111659 is a prime.

It is a Duffinian number.

111691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (111697) 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, 855 + ... + 976.

It is an arithmetic number, because the mean of its divisors is an integer number (28396).

2¹¹¹⁶⁹¹ is an apocalyptic number.

111691 is a deficient number, since it is larger than the sum of its proper divisors (1893).

111691 is an equidigital number, since it uses as much as digits as its factorization.

111691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1892.

The product of its digits is 54, while the sum is 19.

The square root of 111691 is about 334.2020347036. The cubic root of 111691 is about 48.1584750513.

The spelling of 111691 in words is "one hundred eleven thousand, six hundred ninety-one".