561620 has 12 divisors (see below), whose sum is σ = 1179444. Its totient is φ = 224640.

The previous prime is 561607. The next prime is 561667. The reversal of 561620 is 26165.

It can be written as a sum of positive squares in 2 ways, for example, as 169744 + 391876 = 412^2 + 626^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 28081 = 561620 / (5 + 6 + 1 + 6 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 561592 and 561601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14021 + ... + 14060.

It is an arithmetic number, because the mean of its divisors is an integer number (98287).

2⁵⁶¹⁶²⁰ is an apocalyptic number.

It is an amenable number.

561620 is an abundant number, since it is smaller than the sum of its proper divisors (617824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561620 is a wasteful number, since it uses less digits than its factorization.

561620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28090 (or 28088 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 561620 is about 749.4131037018. The cubic root of 561620 is about 82.5051114066.

Adding to 561620 its reverse (26165), we get a palindrome (587785).

The spelling of 561620 in words is "five hundred sixty-one thousand, six hundred twenty".