561305 has 4 divisors (see below), whose sum is σ = 673572. Its totient is φ = 449040.

The previous prime is 561277. The next prime is 561307. The reversal of 561305 is 503165.

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 440896 + 120409 = 664^2 + 347^2 .

It is not a de Polignac number, because 561305 - 2¹⁰ = 560281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56126 + ... + 56135.

It is an arithmetic number, because the mean of its divisors is an integer number (168393).

2⁵⁶¹³⁰⁵ is an apocalyptic number.

It is an amenable number.

561305 is a deficient number, since it is larger than the sum of its proper divisors (112267).

561305 is a wasteful number, since it uses less digits than its factorization.

561305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112266.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 561305 is about 749.2029097648. The cubic root of 561305 is about 82.4896834360.

The spelling of 561305 in words is "five hundred sixty-one thousand, three hundred five".