82985209 has 2 divisors, whose sum is σ = 82985210. Its totient is φ = 82985208.

The previous prime is 82985207. The next prime is 82985237. The reversal of 82985209 is 90258928.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59675625 + 23309584 = 7725^2 + 4828^2 .

It is a cyclic number.

It is not a de Polignac number, because 82985209 - 2¹ = 82985207 is a prime.

Together with 82985207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (82985207) 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, 41492604 + 41492605.

It is an arithmetic number, because the mean of its divisors is an integer number (41492605).

Almost surely, 2^82985209 is an apocalyptic number.

It is an amenable number.

82985209 is a deficient number, since it is larger than the sum of its proper divisors (1).

82985209 is an equidigital number, since it uses as much as digits as its factorization.

82985209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 82985209 is about 9109.6217813914. The cubic root of 82985209 is about 436.1811542056.

The spelling of 82985209 in words is "eighty-two million, nine hundred eighty-five thousand, two hundred nine".