561009 has 4 divisors (see below), whose sum is σ = 748016.
Its totient is φ = 374004.
The previous prime is 560977. The next prime is 561019. The reversal of 561009 is 900165.
561009 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, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is not a de Polignac number, because 561009 - 25 = 560977 is a prime.
It is a D-number.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (561019) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93499 + ... + 93504.
It is an arithmetic number, because the mean of its divisors is an integer number (187004).
2561009 is an apocalyptic number.
It is an amenable number.
561009 is a deficient number, since it is larger than the sum of its proper divisors (187007).
561009 is a wasteful number, since it uses less digits than its factorization.
561009 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 187006.
The product of its (nonzero) digits is 270, while the sum is 21.
The square root of 561009 is about 749.0053404349.
The cubic root of 561009 is about 82.4751807803.
The spelling of 561009 in words is "five hundred sixty-one thousand, nine".