2005409 has 4 divisors (see below), whose sum is σ = 2291904. Its totient is φ = 1718916.

The previous prime is 2005397. The next prime is 2005417. The reversal of 2005409 is 9045002.

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: 9045002 = 2 ⋅4522501.

It is a cyclic number.

It is not a de Polignac number, because 2005409 - 2¹² = 2001313 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2005429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143237 + ... + 143250.

It is an arithmetic number, because the mean of its divisors is an integer number (572976).

2^2005409 is an apocalyptic number.

It is an amenable number.

2005409 is a deficient number, since it is larger than the sum of its proper divisors (286495).

2005409 is an equidigital number, since it uses as much as digits as its factorization.

2005409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286494.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 2005409 is about 1416.1246414070. The cubic root of 2005409 is about 126.1055846316.

The spelling of 2005409 in words is "two million, five thousand, four hundred nine".