563661 has 24 divisors (see below), whose sum is σ = 973440. Its totient is φ = 307296.

The previous prime is 563657. The next prime is 563663. The reversal of 563661 is 166365.

563661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 563661 - 2² = 563657 is a prime.

It is a Curzon number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (563663) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1255 + ... + 1643.

It is an arithmetic number, because the mean of its divisors is an integer number (40560).

2⁵⁶³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

563661 is a deficient number, since it is larger than the sum of its proper divisors (409779).

563661 is a wasteful number, since it uses less digits than its factorization.

563661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 422 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 563661 is about 750.7736010276. The cubic root of 563661 is about 82.6049353421.

The spelling of 563661 in words is "five hundred sixty-three thousand, six hundred sixty-one".