111531 has 16 divisors (see below), whose sum is σ = 175104. Its totient is φ = 61824.

The previous prime is 111521. The next prime is 111533. The reversal of 111531 is 135111.

111531 = T₁₇₅ + T₁₇₆ + ... + T₁₈₁.

It is not a de Polignac number, because 111531 - 2⁶ = 111467 is a prime.

It is a super-2 number, since 2×111531² = 24878327922, which contains 22 as substring.

It is a nialpdrome in base 7.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 111531.

It is not an unprimeable number, because it can be changed into a prime (111533) 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 15 ways as a sum of consecutive naturals, for example, 931 + ... + 1043.

It is an arithmetic number, because the mean of its divisors is an integer number (10944).

2¹¹¹⁵³¹ is an apocalyptic number.

111531 is a deficient number, since it is larger than the sum of its proper divisors (63573).

111531 is a wasteful number, since it uses less digits than its factorization.

111531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170.

The product of its digits is 15, while the sum is 12.

The square root of 111531 is about 333.9625727533. The cubic root of 111531 is about 48.1354680102.

Adding to 111531 its reverse (135111), we get a palindrome (246642).

The spelling of 111531 in words is "one hundred eleven thousand, five hundred thirty-one".