85166627809 has 2 divisors, whose sum is σ = 85166627810. Its totient is φ = 85166627808.

The previous prime is 85166627783. The next prime is 85166627813. The reversal of 85166627809 is 90872666158.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47381099584 + 37785528225 = 217672^2 + 194385^2 .

It is a cyclic number.

It is not a de Polignac number, because 85166627809 - 2⁷ = 85166627681 is a prime.

It is not a weakly prime, because it can be changed into another prime (85166627869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42583313904 + 42583313905.

It is an arithmetic number, because the mean of its divisors is an integer number (42583313905).

Almost surely, 2^85166627809 is an apocalyptic number.

It is an amenable number.

85166627809 is a deficient number, since it is larger than the sum of its proper divisors (1).

85166627809 is an equidigital number, since it uses as much as digits as its factorization.

85166627809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8709120, while the sum is 58.

The spelling of 85166627809 in words is "eighty-five billion, one hundred sixty-six million, six hundred twenty-seven thousand, eight hundred nine".