111031312181 has 2 divisors, whose sum is σ = 111031312182. Its totient is φ = 111031312180.

The previous prime is 111031312157. The next prime is 111031312213. The reversal of 111031312181 is 181213130111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72446567281 + 38584744900 = 269159^2 + 196430^2 .

It is a cyclic number.

It is not a de Polignac number, because 111031312181 - 2¹⁸ = 111031050037 is a prime.

It is a super-2 number, since 2×111031312181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111031312141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55515656090 + 55515656091.

It is an arithmetic number, because the mean of its divisors is an integer number (55515656091).

Almost surely, 2^111031312181 is an apocalyptic number.

It is an amenable number.

111031312181 is a deficient number, since it is larger than the sum of its proper divisors (1).

111031312181 is an equidigital number, since it uses as much as digits as its factorization.

111031312181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 23.

Adding to 111031312181 its reverse (181213130111), we get a palindrome (292244442292).

The spelling of 111031312181 in words is "one hundred eleven billion, thirty-one million, three hundred twelve thousand, one hundred eighty-one".