6511650065561 has 2 divisors, whose sum is σ = 6511650065562. Its totient is φ = 6511650065560.

The previous prime is 6511650065477. The next prime is 6511650065573. The reversal of 6511650065561 is 1655600561156.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3582010464400 + 2929639601161 = 1892620^2 + 1711619^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6511650065561 is a prime.

It is not a weakly prime, because it can be changed into another prime (6511650065161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3255825032780 + 3255825032781.

It is an arithmetic number, because the mean of its divisors is an integer number (3255825032781).

Almost surely, 2^{6511650065561} is an apocalyptic number.

It is an amenable number.

6511650065561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6511650065561 is an equidigital number, since it uses as much as digits as its factorization.

6511650065561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 810000, while the sum is 47.

The spelling of 6511650065561 in words is "six trillion, five hundred eleven billion, six hundred fifty million, sixty-five thousand, five hundred sixty-one".