Adding to 6209 its sum of digits (17), we get a palindrome (6226).
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9026 = 2 ⋅4513.
It is a cyclic number.
It is a Duffinian number.
It is a zygodrome in base 3.
26209 is an apocalyptic number.
It is an amenable number.
6209 is an equidigital number, since it uses as much as digits as its factorization.
6209 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 894.
The square root of 6209 is about 78.7972080724. The cubic root of 6209 is about 18.3797903502.
The spelling of 6209 in words is "six thousand, two hundred nine".