31181 has 2 divisors, whose sum is σ = 31182. Its totient is φ = 31180.

The previous prime is 31177. The next prime is 31183. The reversal of 31181 is 18113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17956 + 13225 = 134^2 + 115^2 .

It is a cyclic number.

It is not a de Polignac number, because 31181 - 2² = 31177 is a prime.

It is a super-2 number, since 2×31181² = 1944509522, which contains 22 as substring.

Together with 31183, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 13 and base 16.

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 31181.

It is not a weakly prime, because it can be changed into another prime (31183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15590 + 15591.

It is an arithmetic number, because the mean of its divisors is an integer number (15591).

2³¹¹⁸¹ is an apocalyptic number.

It is an amenable number.

31181 is a deficient number, since it is larger than the sum of its proper divisors (1).

31181 is an equidigital number, since it uses as much as digits as its factorization.

31181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24, while the sum is 14.

The square root of 31181 is about 176.5814259768. The cubic root of 31181 is about 31.4748266167.

Adding to 31181 its reverse (18113), we get a palindrome (49294).

It can be divided in two parts, 31 and 181, that added together give a palindrome (212).

The spelling of 31181 in words is "thirty-one thousand, one hundred eighty-one".