231123105656561 has 2 divisors, whose sum is σ = 231123105656562. Its totient is φ = 231123105656560.

The previous prime is 231123105656549. The next prime is 231123105656623. The reversal of 231123105656561 is 165656501321132.

231123105656561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179125031737600 + 51998073918961 = 13383760^2 + 7210969^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231123105656561 is a prime.

It is not a weakly prime, because it can be changed into another prime (231123105646561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115561552828280 + 115561552828281.

It is an arithmetic number, because the mean of its divisors is an integer number (115561552828281).

Almost surely, 2^{231123105656561} is an apocalyptic number.

It is an amenable number.

231123105656561 is a deficient number, since it is larger than the sum of its proper divisors (1).

231123105656561 is an equidigital number, since it uses as much as digits as its factorization.

231123105656561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972000, while the sum is 47.

Adding to 231123105656561 its reverse (165656501321132), we get a palindrome (396779606977693).

The spelling of 231123105656561 in words is "two hundred thirty-one trillion, one hundred twenty-three billion, one hundred five million, six hundred fifty-six thousand, five hundred sixty-one".