231131224861 has 2 divisors, whose sum is σ = 231131224862. Its totient is φ = 231131224860.

The previous prime is 231131224823. The next prime is 231131224957. The reversal of 231131224861 is 168422131132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 230573792761 + 557432100 = 480181^2 + 23610^2 .

It is a cyclic number.

It is not a de Polignac number, because 231131224861 - 2⁹ = 231131224349 is a prime.

It is a super-2 number, since 2×231131224861² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231131224661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115565612430 + 115565612431.

It is an arithmetic number, because the mean of its divisors is an integer number (115565612431).

Almost surely, 2^231131224861 is an apocalyptic number.

It is an amenable number.

231131224861 is a deficient number, since it is larger than the sum of its proper divisors (1).

231131224861 is an equidigital number, since it uses as much as digits as its factorization.

231131224861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 34.

Adding to 231131224861 its reverse (168422131132), we get a palindrome (399553355993).

The spelling of 231131224861 in words is "two hundred thirty-one billion, one hundred thirty-one million, two hundred twenty-four thousand, eight hundred sixty-one".