8390820209 has 2 divisors, whose sum is σ = 8390820210. Its totient is φ = 8390820208.

The previous prime is 8390820181. The next prime is 8390820247. The reversal of 8390820209 is 9020280938.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5550250000 + 2840570209 = 74500^2 + 53297^2 .

It is a cyclic number.

It is not a de Polignac number, because 8390820209 - 2¹² = 8390816113 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 (8390820259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4195410104 + 4195410105.

It is an arithmetic number, because the mean of its divisors is an integer number (4195410105).

Almost surely, 2^8390820209 is an apocalyptic number.

It is an amenable number.

8390820209 is a deficient number, since it is larger than the sum of its proper divisors (1).

8390820209 is an equidigital number, since it uses as much as digits as its factorization.

8390820209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 8390820209 is about 91601.4203437916. The cubic root of 8390820209 is about 2032.0519432318.

The spelling of 8390820209 in words is "eight billion, three hundred ninety million, eight hundred twenty thousand, two hundred nine".