3561209 has 2 divisors, whose sum is σ = 3561210. Its totient is φ = 3561208.

The previous prime is 3561203. The next prime is 3561221. The reversal of 3561209 is 9021653.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2795584 + 765625 = 1672^2 + 875^2 .

It is a cyclic number.

It is not a de Polignac number, because 3561209 - 2⁴ = 3561193 is a prime.

It is not a weakly prime, because it can be changed into another prime (3561203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1780604 + 1780605.

It is an arithmetic number, because the mean of its divisors is an integer number (1780605).

Almost surely, 2^3561209 is an apocalyptic number.

It is an amenable number.

3561209 is a deficient number, since it is larger than the sum of its proper divisors (1).

3561209 is an equidigital number, since it uses as much as digits as its factorization.

3561209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 3561209 is about 1887.1165835740. The cubic root of 3561209 is about 152.7094175662.

The spelling of 3561209 in words is "three million, five hundred sixty-one thousand, two hundred nine".