985365809 has 2 divisors, whose sum is σ = 985365810. Its totient is φ = 985365808.

The previous prime is 985365803. The next prime is 985365817. The reversal of 985365809 is 908563589.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 591462400 + 393903409 = 24320^2 + 19847^2 .

It is a cyclic number.

It is not a de Polignac number, because 985365809 - 2¹⁶ = 985300273 is a prime.

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 (985365803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 492682904 + 492682905.

It is an arithmetic number, because the mean of its divisors is an integer number (492682905).

Almost surely, 2^985365809 is an apocalyptic number.

It is an amenable number.

985365809 is a deficient number, since it is larger than the sum of its proper divisors (1).

985365809 is an equidigital number, since it uses as much as digits as its factorization.

985365809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2332800, while the sum is 53.

The square root of 985365809 is about 31390.5369339233. The cubic root of 985365809 is about 995.0979454603.

The spelling of 985365809 in words is "nine hundred eighty-five million, three hundred sixty-five thousand, eight hundred nine".