115691 has 4 divisors (see below), whose sum is σ = 121800. Its totient is φ = 109584.

The previous prime is 115679. The next prime is 115693. The reversal of 115691 is 196511.

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-115691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115693) 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, 3026 + ... + 3063.

It is an arithmetic number, because the mean of its divisors is an integer number (30450).

2¹¹⁵⁶⁹¹ is an apocalyptic number.

115691 is a deficient number, since it is larger than the sum of its proper divisors (6109).

115691 is an equidigital number, since it uses as much as digits as its factorization.

115691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6108.

The product of its digits is 270, while the sum is 23.

The square root of 115691 is about 340.1337972034. The cubic root of 115691 is about 48.7266467151.

The spelling of 115691 in words is "one hundred fifteen thousand, six hundred ninety-one".