231223212161 has 2 divisors, whose sum is σ = 231223212162. Its totient is φ = 231223212160.

The previous prime is 231223212007. The next prime is 231223212169. The reversal of 231223212161 is 161212322132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171176650225 + 60046561936 = 413735^2 + 245044^2 .

It is a cyclic number.

It is not a de Polignac number, because 231223212161 - 2³⁰ = 230149470337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 231223212161.

It is not a weakly prime, because it can be changed into another prime (231223212169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115611606080 + 115611606081.

It is an arithmetic number, because the mean of its divisors is an integer number (115611606081).

Almost surely, 2^231223212161 is an apocalyptic number.

It is an amenable number.

231223212161 is a deficient number, since it is larger than the sum of its proper divisors (1).

231223212161 is an equidigital number, since it uses as much as digits as its factorization.

231223212161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 26.

Adding to 231223212161 its reverse (161212322132), we get a palindrome (392435534293).

The spelling of 231223212161 in words is "two hundred thirty-one billion, two hundred twenty-three million, two hundred twelve thousand, one hundred sixty-one".