318181 has 2 divisors, whose sum is σ = 318182. Its totient is φ = 318180.

The previous prime is 318179. The next prime is 318191. The reversal of 318181 is 181813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 260100 + 58081 = 510^2 + 241^2 .

It is an emirp because it is prime and its reverse (181813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 318181 - 2¹ = 318179 is a prime.

It is a super-2 number, since 2×318181² = 202478297522, which contains 22 as substring.

Together with 318179, it forms a pair of twin primes.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (318161) 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 as a sum of consecutive naturals, namely, 159090 + 159091.

It is an arithmetic number, because the mean of its divisors is an integer number (159091).

2³¹⁸¹⁸¹ is an apocalyptic number.

It is an amenable number.

318181 is a deficient number, since it is larger than the sum of its proper divisors (1).

318181 is an equidigital number, since it uses as much as digits as its factorization.

318181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 22.

The square root of 318181 is about 564.0753495766. The cubic root of 318181 is about 68.2691895930.

Adding to 318181 its reverse (181813), we get a palindrome (499994).

The spelling of 318181 in words is "three hundred eighteen thousand, one hundred eighty-one".