2005609 has 4 divisors (see below), whose sum is σ = 2123604. Its totient is φ = 1887616.

The previous prime is 2005579. The next prime is 2005613. The reversal of 2005609 is 9065002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 632025 + 1373584 = 795^2 + 1172^2 .

It is a cyclic number.

It is not a de Polignac number, because 2005609 - 2¹⁹ = 1481321 is a prime.

It is a Duffinian number.

2005609 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2005609.

It is not an unprimeable number, because it can be changed into a prime (2015609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58972 + ... + 59005.

It is an arithmetic number, because the mean of its divisors is an integer number (530901).

2^2005609 is an apocalyptic number.

It is an amenable number.

2005609 is a deficient number, since it is larger than the sum of its proper divisors (117995).

2005609 is a wasteful number, since it uses less digits than its factorization.

2005609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117994.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 2005609 is about 1416.1952548995. The cubic root of 2005609 is about 126.1097766740.

The spelling of 2005609 in words is "two million, five thousand, six hundred nine".