85171409 has 2 divisors, whose sum is σ = 85171410. Its totient is φ = 85171408.

The previous prime is 85171367. The next prime is 85171417. The reversal of 85171409 is 90417158.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60450625 + 24720784 = 7775^2 + 4972^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85171409 is a prime.

It is a super-2 number, since 2×85171409² = 14508337822090562, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (85171439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42585704 + 42585705.

It is an arithmetic number, because the mean of its divisors is an integer number (42585705).

Almost surely, 2^85171409 is an apocalyptic number.

It is an amenable number.

85171409 is a deficient number, since it is larger than the sum of its proper divisors (1).

85171409 is an equidigital number, since it uses as much as digits as its factorization.

85171409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 85171409 is about 9228.8357337207. The cubic root of 85171409 is about 439.9783202128.

The spelling of 85171409 in words is "eighty-five million, one hundred seventy-one thousand, four hundred nine".