115531 has 4 divisors (see below), whose sum is σ = 124432. Its totient is φ = 106632.

The previous prime is 115523. The next prime is 115547. The reversal of 115531 is 135511.

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

It is a cyclic number.

It is not a de Polignac number, because 115531 - 2³ = 115523 is a prime.

It is a super-2 number, since 2×115531² = 26694823922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115561) 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, 4431 + ... + 4456.

It is an arithmetic number, because the mean of its divisors is an integer number (31108).

2¹¹⁵⁵³¹ is an apocalyptic number.

115531 is a deficient number, since it is larger than the sum of its proper divisors (8901).

115531 is an equidigital number, since it uses as much as digits as its factorization.

115531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8900.

The product of its digits is 75, while the sum is 16.

The square root of 115531 is about 339.8985142657. The cubic root of 115531 is about 48.7041734593.

It can be divided in two parts, 115 and 531, that added together give a palindrome (646).

The spelling of 115531 in words is "one hundred fifteen thousand, five hundred thirty-one".