85641723857 has 2 divisors, whose sum is σ = 85641723858. Its totient is φ = 85641723856.

The previous prime is 85641723821. The next prime is 85641723877. The reversal of 85641723857 is 75832714658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79041948736 + 6599775121 = 281144^2 + 81239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85641723857 is a prime.

It is not a weakly prime, because it can be changed into another prime (85641723877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42820861928 + 42820861929.

It is an arithmetic number, because the mean of its divisors is an integer number (42820861929).

Almost surely, 2^85641723857 is an apocalyptic number.

It is an amenable number.

85641723857 is a deficient number, since it is larger than the sum of its proper divisors (1).

85641723857 is an equidigital number, since it uses as much as digits as its factorization.

85641723857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11289600, while the sum is 56.

The spelling of 85641723857 in words is "eighty-five billion, six hundred forty-one million, seven hundred twenty-three thousand, eight hundred fifty-seven".