185531 has 2 divisors, whose sum is σ = 185532. Its totient is φ = 185530.

The previous prime is 185527. The next prime is 185533. The reversal of 185531 is 135581.

It is a strong prime.

It is an emirp because it is prime and its reverse (135581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 185531 - 2² = 185527 is a prime.

It is a super-2 number, since 2×185531² = 68843503922, which contains 22 as substring.

Together with 185533, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 185497 and 185506.

It is not a weakly prime, because it can be changed into another prime (185533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 92765 + 92766.

It is an arithmetic number, because the mean of its divisors is an integer number (92766).

2¹⁸⁵⁵³¹ is an apocalyptic number.

185531 is a deficient number, since it is larger than the sum of its proper divisors (1).

185531 is an equidigital number, since it uses as much as digits as its factorization.

185531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 600, while the sum is 23.

The square root of 185531 is about 430.7330960119. The cubic root of 185531 is about 57.0346562612.

The spelling of 185531 in words is "one hundred eighty-five thousand, five hundred thirty-one".