3656209 has 4 divisors (see below), whose sum is σ = 3697380. Its totient is φ = 3615040.

The previous prime is 3656183. The next prime is 3656231. The reversal of 3656209 is 9026563.

3656209 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.

It can be written as a sum of positive squares in 2 ways, for example, as 1096209 + 2560000 = 1047^2 + 1600^2 .

It is a cyclic number.

It is not a de Polignac number, because 3656209 - 2¹⁵ = 3623441 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3656239) 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, 20452 + ... + 20629.

It is an arithmetic number, because the mean of its divisors is an integer number (924345).

Almost surely, 2^3656209 is an apocalyptic number.

It is an amenable number.

3656209 is a deficient number, since it is larger than the sum of its proper divisors (41171).

3656209 is an equidigital number, since it uses as much as digits as its factorization.

3656209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41170.

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 3656209 is about 1912.1215965519. The cubic root of 3656209 is about 154.0554278469.

The spelling of 3656209 in words is "three million, six hundred fifty-six thousand, two hundred nine".