85071509 has 2 divisors, whose sum is σ = 85071510. Its totient is φ = 85071508.

The previous prime is 85071491. The next prime is 85071517. The reversal of 85071509 is 90517058.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79263409 + 5808100 = 8903^2 + 2410^2 .

It is a cyclic number.

It is not a de Polignac number, because 85071509 - 2¹² = 85067413 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85071559) 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, 42535754 + 42535755.

It is an arithmetic number, because the mean of its divisors is an integer number (42535755).

Almost surely, 2^85071509 is an apocalyptic number.

It is an amenable number.

85071509 is a deficient number, since it is larger than the sum of its proper divisors (1).

85071509 is an equidigital number, since it uses as much as digits as its factorization.

85071509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12600, while the sum is 35.

The square root of 85071509 is about 9223.4217620144. The cubic root of 85071509 is about 439.8062318292.

The spelling of 85071509 in words is "eighty-five million, seventy-one thousand, five hundred nine".