561506 has 8 divisors (see below), whose sum is σ = 918864. Its totient is φ = 255220.

The previous prime is 561461. The next prime is 561521. The reversal of 561506 is 605165.

561506 = T₁₈ + T₁₉ + ... + T₁₄₉.

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

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 12740 + ... + 12783.

It is an arithmetic number, because the mean of its divisors is an integer number (114858).

2⁵⁶¹⁵⁰⁶ is an apocalyptic number.

561506 is a deficient number, since it is larger than the sum of its proper divisors (357358).

561506 is a wasteful number, since it uses less digits than its factorization.

561506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25536.

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

The square root of 561506 is about 749.3370403230. The cubic root of 561506 is about 82.4995286168.

The spelling of 561506 in words is "five hundred sixty-one thousand, five hundred six".