561901 has 4 divisors (see below), whose sum is σ = 594972. Its totient is φ = 528832.

The previous prime is 561839. The next prime is 561907. The reversal of 561901 is 109165.

561901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 455625 + 106276 = 675^2 + 326^2 .

It is a cyclic number.

It is not a de Polignac number, because 561901 - 2⁹ = 561389 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

561901 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16510 + ... + 16543.

It is an arithmetic number, because the mean of its divisors is an integer number (148743).

2⁵⁶¹⁹⁰¹ is an apocalyptic number.

It is an amenable number.

561901 is a deficient number, since it is larger than the sum of its proper divisors (33071).

561901 is a wasteful number, since it uses less digits than its factorization.

561901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33070.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 561901 is about 749.6005602986. The cubic root of 561901 is about 82.5188692683.

The spelling of 561901 in words is "five hundred sixty-one thousand, nine hundred one".