331121020321261 has 2 divisors, whose sum is σ = 331121020321262. Its totient is φ = 331121020321260.

The previous prime is 331121020321193. The next prime is 331121020321277. The reversal of 331121020321261 is 162123020121133.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 229468872132900 + 101652148188361 = 15148230^2 + 10082269^2 .

It is an emirp because it is prime and its reverse (162123020121133) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 331121020321261 - 2⁹ = 331121020320749 is a prime.

It is a super-2 number, since 2×331121020321261² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (331121020327261) 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, 165560510160630 + 165560510160631.

It is an arithmetic number, because the mean of its divisors is an integer number (165560510160631).

Almost surely, 2^{331121020321261} is an apocalyptic number.

It is an amenable number.

331121020321261 is a deficient number, since it is larger than the sum of its proper divisors (1).

331121020321261 is an equidigital number, since it uses as much as digits as its factorization.

331121020321261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

Adding to 331121020321261 its reverse (162123020121133), we get a palindrome (493244040442394).

The spelling of 331121020321261 in words is "three hundred thirty-one trillion, one hundred twenty-one billion, twenty million, three hundred twenty-one thousand, two hundred sixty-one".