561605 has 8 divisors (see below), whose sum is σ = 735264. Its totient is φ = 408400.

The previous prime is 561599. The next prime is 561607. The reversal of 561605 is 506165.

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

It is a de Polignac number, because none of the positive numbers 2^k-561605 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561607) 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, 5051 + ... + 5160.

It is an arithmetic number, because the mean of its divisors is an integer number (91908).

2⁵⁶¹⁶⁰⁵ is an apocalyptic number.

561605 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

561605 is a deficient number, since it is larger than the sum of its proper divisors (173659).

561605 is a wasteful number, since it uses less digits than its factorization.

561605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10227.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 561605 is about 749.4030958036. The cubic root of 561605 is about 82.5043768722.

It can be divided in two parts, 56160 and 5, that added together give a palindrome (56165).

The spelling of 561605 in words is "five hundred sixty-one thousand, six hundred five".