505106561561 has 16 divisors (see below), whose sum is σ = 579857187840. Its totient is φ = 431004542400.

The previous prime is 505106561431. The next prime is 505106561579. The reversal of 505106561561 is 165165601505.

It is a cyclic number.

It is not a de Polignac number, because 505106561561 - 2¹⁸ = 505106299417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (505106561261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18319736 + ... + 18347286.

It is an arithmetic number, because the mean of its divisors is an integer number (36241074240).

Almost surely, 2^505106561561 is an apocalyptic number.

It is an amenable number.

505106561561 is a deficient number, since it is larger than the sum of its proper divisors (74750626279).

505106561561 is a wasteful number, since it uses less digits than its factorization.

505106561561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39224.

The product of its (nonzero) digits is 135000, while the sum is 41.

The spelling of 505106561561 in words is "five hundred five billion, one hundred six million, five hundred sixty-one thousand, five hundred sixty-one".