84569809 has 2 divisors, whose sum is σ = 84569810. Its totient is φ = 84569808.

The previous prime is 84569791. The next prime is 84569819. The reversal of 84569809 is 90896548.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48233025 + 36336784 = 6945^2 + 6028^2 .

It is a cyclic number.

It is not a de Polignac number, because 84569809 - 2¹¹ = 84567761 is a prime.

It is not a weakly prime, because it can be changed into another prime (84569819) 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, 42284904 + 42284905.

It is an arithmetic number, because the mean of its divisors is an integer number (42284905).

Almost surely, 2^84569809 is an apocalyptic number.

It is an amenable number.

84569809 is a deficient number, since it is larger than the sum of its proper divisors (1).

84569809 is an equidigital number, since it uses as much as digits as its factorization.

84569809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 622080, while the sum is 49.

The square root of 84569809 is about 9196.1844805332. The cubic root of 84569809 is about 438.9399568153.

The spelling of 84569809 in words is "eighty-four million, five hundred sixty-nine thousand, eight hundred nine".