561666505604 has 24 divisors (see below), whose sum is σ = 1040762361240. Its totient is φ = 264306699776.

The previous prime is 561666505577. The next prime is 561666505643. The reversal of 561666505604 is 406505666165.

561666505604 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 157412149504 + 404254356100 = 396752^2 + 635810^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3258662 + ... + 3426690.

It is an arithmetic number, because the mean of its divisors is an integer number (43365098385).

Almost surely, 2^561666505604 is an apocalyptic number.

It is an amenable number.

561666505604 is a deficient number, since it is larger than the sum of its proper divisors (479095855636).

561666505604 is a wasteful number, since it uses less digits than its factorization.

561666505604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217207 (or 217205 counting only the distinct ones).

The product of its (nonzero) digits is 3888000, while the sum is 50.

The spelling of 561666505604 in words is "five hundred sixty-one billion, six hundred sixty-six million, five hundred five thousand, six hundred four".