8381209 has 2 divisors, whose sum is σ = 8381210. Its totient is φ = 8381208.

The previous prime is 8381207. The next prime is 8381227. The reversal of 8381209 is 9021838.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7683984 + 697225 = 2772^2 + 835^2 .

It is a cyclic number.

It is not a de Polignac number, because 8381209 - 2¹ = 8381207 is a prime.

Together with 8381207, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8381207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4190604 + 4190605.

It is an arithmetic number, because the mean of its divisors is an integer number (4190605).

Almost surely, 2^8381209 is an apocalyptic number.

It is an amenable number.

8381209 is a deficient number, since it is larger than the sum of its proper divisors (1).

8381209 is an equidigital number, since it uses as much as digits as its factorization.

8381209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 8381209 is about 2895.0317787548. The cubic root of 8381209 is about 203.1275780028.

The spelling of 8381209 in words is "eight million, three hundred eighty-one thousand, two hundred nine".