6821128458161 has 2 divisors, whose sum is σ = 6821128458162. Its totient is φ = 6821128458160.

The previous prime is 6821128458119. The next prime is 6821128458239. The reversal of 6821128458161 is 1618548211286.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4944107896225 + 1877020561936 = 2223535^2 + 1370044^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6821128458161 is a prime.

It is a super-2 number, since 2×6821128458161² (a number of 26 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6821128458761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3410564229080 + 3410564229081.

It is an arithmetic number, because the mean of its divisors is an integer number (3410564229081).

Almost surely, 2^{6821128458161} is an apocalyptic number.

It is an amenable number.

6821128458161 is a deficient number, since it is larger than the sum of its proper divisors (1).

6821128458161 is an equidigital number, since it uses as much as digits as its factorization.

6821128458161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1474560, while the sum is 53.

The spelling of 6821128458161 in words is "six trillion, eight hundred twenty-one billion, one hundred twenty-eight million, four hundred fifty-eight thousand, one hundred sixty-one".