2405209 has 2 divisors, whose sum is σ = 2405210. Its totient is φ = 2405208.

The previous prime is 2405203. The next prime is 2405213. The reversal of 2405209 is 9025042.

It is a happy number.

2405209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2039184 + 366025 = 1428^2 + 605^2 .

It is a cyclic number.

It is not a de Polignac number, because 2405209 - 2¹¹ = 2403161 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2405209.

It is not a weakly prime, because it can be changed into another prime (2405203) 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 as a sum of consecutive naturals, namely, 1202604 + 1202605.

It is an arithmetic number, because the mean of its divisors is an integer number (1202605).

2^2405209 is an apocalyptic number.

It is an amenable number.

2405209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2405209 is an equidigital number, since it uses as much as digits as its factorization.

2405209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 2405209 is about 1550.8736247677. The cubic root of 2405209 is about 133.9833832518.

The spelling of 2405209 in words is "two million, four hundred five thousand, two hundred nine".