85721875717 has 2 divisors, whose sum is σ = 85721875718. Its totient is φ = 85721875716.

The previous prime is 85721875703. The next prime is 85721875741. The reversal of 85721875717 is 71757812758.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83562043041 + 2159832676 = 289071^2 + 46474^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85721875717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85721875747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42860937858 + 42860937859.

It is an arithmetic number, because the mean of its divisors is an integer number (42860937859).

Almost surely, 2^85721875717 is an apocalyptic number.

It is an amenable number.

85721875717 is a deficient number, since it is larger than the sum of its proper divisors (1).

85721875717 is an equidigital number, since it uses as much as digits as its factorization.

85721875717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7683200, while the sum is 58.

The spelling of 85721875717 in words is "eighty-five billion, seven hundred twenty-one million, eight hundred seventy-five thousand, seven hundred seventeen".