85661857 has 2 divisors, whose sum is σ = 85661858. Its totient is φ = 85661856.

The previous prime is 85661843. The next prime is 85661909. The reversal of 85661857 is 75816658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63345681 + 22316176 = 7959^2 + 4724^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85661857 is a prime.

It is not a weakly prime, because it can be changed into another prime (85661057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42830928 + 42830929.

It is an arithmetic number, because the mean of its divisors is an integer number (42830929).

Almost surely, 2^85661857 is an apocalyptic number.

It is an amenable number.

85661857 is a deficient number, since it is larger than the sum of its proper divisors (1).

85661857 is an equidigital number, since it uses as much as digits as its factorization.

85661857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 403200, while the sum is 46.

The square root of 85661857 is about 9255.3690904253. The cubic root of 85661857 is about 440.8212228460.

The spelling of 85661857 in words is "eighty-five million, six hundred sixty-one thousand, eight hundred fifty-seven".