561921 has 8 divisors (see below), whose sum is σ = 757344. Its totient is φ = 370560.

The previous prime is 561917. The next prime is 561923. The reversal of 561921 is 129165.

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

It is not a de Polignac number, because 561921 - 2² = 561917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 561891 and 561900.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 561921.

It is not an unprimeable number, because it can be changed into a prime (561923) 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, 675 + ... + 1256.

It is an arithmetic number, because the mean of its divisors is an integer number (94668).

2⁵⁶¹⁹²¹ is an apocalyptic number.

It is an amenable number.

561921 is a deficient number, since it is larger than the sum of its proper divisors (195423).

561921 is a wasteful number, since it uses less digits than its factorization.

561921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2031.

The product of its digits is 540, while the sum is 24.

The square root of 561921 is about 749.6139006182. The cubic root of 561921 is about 82.5198483006.

The spelling of 561921 in words is "five hundred sixty-one thousand, nine hundred twenty-one".