71561806653217 has 2 divisors, whose sum is σ = 71561806653218. Its totient is φ = 71561806653216.

The previous prime is 71561806653187. The next prime is 71561806653251. The reversal of 71561806653217 is 71235660816517.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53991281711376 + 17570524941841 = 7347876^2 + 4191721^2 .

It is a cyclic number.

It is not a de Polignac number, because 71561806653217 - 2¹¹ = 71561806651169 is a prime.

It is a super-3 number, since 3×71561806653217³ (a number of 43 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (71561806653317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35780903326608 + 35780903326609.

It is an arithmetic number, because the mean of its divisors is an integer number (35780903326609).

Almost surely, 2^{71561806653217} is an apocalyptic number.

It is an amenable number.

71561806653217 is a deficient number, since it is larger than the sum of its proper divisors (1).

71561806653217 is an equidigital number, since it uses as much as digits as its factorization.

71561806653217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12700800, while the sum is 58.

The spelling of 71561806653217 in words is "seventy-one trillion, five hundred sixty-one billion, eight hundred six million, six hundred fifty-three thousand, two hundred seventeen".