561109 has 2 divisors, whose sum is σ = 561110. Its totient is φ = 561108.

The previous prime is 561103. The next prime is 561161. The reversal of 561109 is 901165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 555025 + 6084 = 745^2 + 78^2 .

It is a cyclic number.

It is not a de Polignac number, because 561109 - 2³ = 561101 is a prime.

561109 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 561109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561101) 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, 280554 + 280555.

It is an arithmetic number, because the mean of its divisors is an integer number (280555).

2⁵⁶¹¹⁰⁹ is an apocalyptic number.

It is an amenable number.

561109 is a deficient number, since it is larger than the sum of its proper divisors (1).

561109 is an equidigital number, since it uses as much as digits as its factorization.

561109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 561109 is about 749.0720926586. The cubic root of 561109 is about 82.4800808966.

The spelling of 561109 in words is "five hundred sixty-one thousand, one hundred nine".