240209 has 2 divisors, whose sum is σ = 240210. Its totient is φ = 240208.

The previous prime is 240203. The next prime is 240257. The reversal of 240209 is 902042.

240209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 124609 + 115600 = 353^2 + 340^2 .

It is a cyclic number.

It is not a de Polignac number, because 240209 - 2¹⁶ = 174673 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (240203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120104 + 120105.

It is an arithmetic number, because the mean of its divisors is an integer number (120105).

2²⁴⁰²⁰⁹ is an apocalyptic number.

It is an amenable number.

240209 is a deficient number, since it is larger than the sum of its proper divisors (1).

240209 is an equidigital number, since it uses as much as digits as its factorization.

240209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 240209 is about 490.1112118693. Note that the first 3 decimals coincide. The cubic root of 240209 is about 62.1626840962.

The spelling of 240209 in words is "two hundred forty thousand, two hundred nine".