1909 is nontrivially palindromic in base 13.
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 a brilliant number, because the two primes have the same length.
It is a cyclic number.
It is a Duffinian number.
1909 is an undulating number in base 13.
It is a nialpdrome in base 15 and base 16.
It is a congruent number.
It is a 18-hyperperfect number.
It is an amenable number.
1909 is an equidigital number, since it uses as much as digits as its factorization.
1909 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 106.
The square root of 1909 is about 43.6921045499. The cubic root of 1909 is about 12.4051487463.
The spelling of 1909 in words is "one thousand, nine hundred nine".