561643 has 8 divisors (see below), whose sum is σ = 589680. Its totient is φ = 534240.

The previous prime is 561607. The next prime is 561667. The reversal of 561643 is 346165.

561643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 561643 - 2¹⁷ = 430571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3013 + ... + 3193.

It is an arithmetic number, because the mean of its divisors is an integer number (73710).

2⁵⁶¹⁶⁴³ is an apocalyptic number.

561643 is a deficient number, since it is larger than the sum of its proper divisors (28037).

561643 is a wasteful number, since it uses less digits than its factorization.

561643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317.

The product of its digits is 2160, while the sum is 25.

The square root of 561643 is about 749.4284488862. The cubic root of 561643 is about 82.5062376673.

The spelling of 561643 in words is "five hundred sixty-one thousand, six hundred forty-three".