85805309 has 2 divisors, whose sum is σ = 85805310. Its totient is φ = 85805308.

The previous prime is 85805299. The next prime is 85805347. The reversal of 85805309 is 90350858.

It is an a-pointer prime, because the next prime (85805347) can be obtained adding 85805309 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67980025 + 17825284 = 8245^2 + 4222^2 .

It is a cyclic number.

It is not a de Polignac number, because 85805309 - 2¹² = 85801213 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85805389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42902654 + 42902655.

It is an arithmetic number, because the mean of its divisors is an integer number (42902655).

Almost surely, 2^85805309 is an apocalyptic number.

It is an amenable number.

85805309 is a deficient number, since it is larger than the sum of its proper divisors (1).

85805309 is an equidigital number, since it uses as much as digits as its factorization.

85805309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 38.

The square root of 85805309 is about 9263.1155126124. The cubic root of 85805309 is about 441.0671565739.

The spelling of 85805309 in words is "eighty-five million, eight hundred five thousand, three hundred nine".