561409 has 2 divisors, whose sum is σ = 561410. Its totient is φ = 561408.

The previous prime is 561389. The next prime is 561419. The reversal of 561409 is 904165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 378225 + 183184 = 615^2 + 428^2 .

It is a cyclic number.

It is not a de Polignac number, because 561409 - 2⁵ = 561377 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (561419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280704 + 280705.

It is an arithmetic number, because the mean of its divisors is an integer number (280705).

2⁵⁶¹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

561409 is a deficient number, since it is larger than the sum of its proper divisors (1).

561409 is an equidigital number, since it uses as much as digits as its factorization.

561409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 561409 is about 749.2723136484. The cubic root of 561409 is about 82.4947777533.

The spelling of 561409 in words is "five hundred sixty-one thousand, four hundred nine".