561666055 has 12 divisors (see below), whose sum is σ = 698047272. Its totient is φ = 433835360.

The previous prime is 561666041. The next prime is 561666067. The reversal of 561666055 is 550666165.

It is not a de Polignac number, because 561666055 - 2⁵ = 561666023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 561665999 and 561666017.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62581 + ... + 70990.

It is an arithmetic number, because the mean of its divisors is an integer number (58170606).

Almost surely, 2^561666055 is an apocalyptic number.

561666055 is a deficient number, since it is larger than the sum of its proper divisors (136381217).

561666055 is a wasteful number, since it uses less digits than its factorization.

561666055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133634 (or 133605 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 40.

The square root of 561666055 is about 23699.4948258396. The cubic root of 561666055 is about 825.0736659044.

The spelling of 561666055 in words is "five hundred sixty-one million, six hundred sixty-six thousand, fifty-five".