209005 has 4 divisors (see below), whose sum is σ = 250812. Its totient is φ = 167200.

The previous prime is 208997. The next prime is 209021. The reversal of 209005 is 500902.

209005 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 500902 = 2 ⋅250451.

It can be written as a sum of positive squares in 2 ways, for example, as 24964 + 184041 = 158^2 + 429^2 .

It is not a de Polignac number, because 209005 - 2³ = 208997 is a prime.

It is a Duffinian number.

209005 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 209005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20896 + ... + 20905.

It is an arithmetic number, because the mean of its divisors is an integer number (62703).

2²⁰⁹⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

209005 is a deficient number, since it is larger than the sum of its proper divisors (41807).

209005 is an equidigital number, since it uses as much as digits as its factorization.

209005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41806.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 209005 is about 457.1706464768. The cubic root of 209005 is about 59.3451946436.

Adding to 209005 its reverse (500902), we get a palindrome (709907).

It can be divided in two parts, 20 and 9005, that added together give a square (9025 = 95²).

The spelling of 209005 in words is "two hundred nine thousand, five".