331221230090161 has 2 divisors, whose sum is σ = 331221230090162. Its totient is φ = 331221230090160.

The previous prime is 331221230090159. The next prime is 331221230090263. The reversal of 331221230090161 is 161090032122133.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168790920705936 + 162430309384225 = 12991956^2 + 12744815^2 .

It is an emirp because it is prime and its reverse (161090032122133) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 331221230090161 - 2¹ = 331221230090159 is a prime.

Together with 331221230090159, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (331221230091161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165610615045080 + 165610615045081.

It is an arithmetic number, because the mean of its divisors is an integer number (165610615045081).

Almost surely, 2^{331221230090161} is an apocalyptic number.

It is an amenable number.

331221230090161 is a deficient number, since it is larger than the sum of its proper divisors (1).

331221230090161 is an equidigital number, since it uses as much as digits as its factorization.

331221230090161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 34.

The spelling of 331221230090161 in words is "three hundred thirty-one trillion, two hundred twenty-one billion, two hundred thirty million, ninety thousand, one hundred sixty-one".