8085686561 has 2 divisors, whose sum is σ = 8085686562. Its totient is φ = 8085686560.

The previous prime is 8085686551. The next prime is 8085686617. The reversal of 8085686561 is 1656865808.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7204784161 + 880902400 = 84881^2 + 29680^2 .

It is a cyclic number.

It is not a de Polignac number, because 8085686561 - 2²² = 8081492257 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (8085686551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4042843280 + 4042843281.

It is an arithmetic number, because the mean of its divisors is an integer number (4042843281).

Almost surely, 2^8085686561 is an apocalyptic number.

8085686561 is the 48065-th centered heptagonal number.

It is an amenable number.

8085686561 is a deficient number, since it is larger than the sum of its proper divisors (1).

8085686561 is an equidigital number, since it uses as much as digits as its factorization.

8085686561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2764800, while the sum is 53.

The square root of 8085686561 is about 89920.4457339931. The cubic root of 8085686561 is about 2007.1152036704.

The spelling of 8085686561 in words is "eight billion, eighty-five million, six hundred eighty-six thousand, five hundred sixty-one".