6561161616511 has 2 divisors, whose sum is σ = 6561161616512. Its totient is φ = 6561161616510.

The previous prime is 6561161616337. The next prime is 6561161616517. The reversal of 6561161616511 is 1156161611656.

It is a happy number.

6561161616511 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6561161616511 - 2¹⁹ = 6561161092223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6561161616517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280580808255 + 3280580808256.

It is an arithmetic number, because the mean of its divisors is an integer number (3280580808256).

Almost surely, 2^{6561161616511} is an apocalyptic number.

6561161616511 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561161616511 is an equidigital number, since it uses as much as digits as its factorization.

6561161616511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 46.

The spelling of 6561161616511 in words is "six trillion, five hundred sixty-one billion, one hundred sixty-one million, six hundred sixteen thousand, five hundred eleven".