561826 has 4 divisors (see below), whose sum is σ = 842742. Its totient is φ = 280912.

The previous prime is 561809. The next prime is 561829. The reversal of 561826 is 628165.

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

It can be written as a sum of positive squares in only one way, i.e., 421201 + 140625 = 649^2 + 375^2 .

It is a junction number, because it is equal to n+sod(n) for n = 561794 and 561803.

It is not an unprimeable number, because it can be changed into a prime (561829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140455 + ... + 140458.

2⁵⁶¹⁸²⁶ is an apocalyptic number.

561826 is a deficient number, since it is larger than the sum of its proper divisors (280916).

561826 is a wasteful number, since it uses less digits than its factorization.

561826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280915.

The product of its digits is 2880, while the sum is 28.

The square root of 561826 is about 749.5505319857. The cubic root of 561826 is about 82.5151976899.

The spelling of 561826 in words is "five hundred sixty-one thousand, eight hundred twenty-six".