82009 has 2 divisors, whose sum is σ = 82010. Its totient is φ = 82008.

The previous prime is 82007. The next prime is 82013. The reversal of 82009 is 90028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81225 + 784 = 285^2 + 28^2 .

It is a cyclic number.

It is not a de Polignac number, because 82009 - 2¹ = 82007 is a prime.

Together with 82007, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (82003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41004 + 41005.

It is an arithmetic number, because the mean of its divisors is an integer number (41005).

2⁸²⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

82009 is a deficient number, since it is larger than the sum of its proper divisors (1).

82009 is an equidigital number, since it uses as much as digits as its factorization.

82009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 82009 is about 286.3721355160. The cubic root of 82009 is about 43.4464042440.

Adding to 82009 its sum of digits (19), we get a palindrome (82028).

The spelling of 82009 in words is "eighty-two thousand, nine".