6566565561 has 16 divisors (see below), whose sum is σ = 8978466816. Its totient is φ = 4266629136.

The previous prime is 6566565517. The next prime is 6566565587. The reversal of 6566565561 is 1655656656.

It is not a de Polignac number, because 6566565561 - 2¹⁵ = 6566532793 is a prime.

It is a super-2 number, since 2×6566565561² = 86239566533822489442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6566565461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4756 + ... + 114698.

It is an arithmetic number, because the mean of its divisors is an integer number (561154176).

Almost surely, 2^6566565561 is an apocalyptic number.

It is an amenable number.

6566565561 is a deficient number, since it is larger than the sum of its proper divisors (2411901255).

6566565561 is a wasteful number, since it uses less digits than its factorization.

6566565561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110452.

The product of its digits is 4860000, while the sum is 51.

The square root of 6566565561 is about 81034.3480321771. The cubic root of 6566565561 is about 1872.6046388025.

The spelling of 6566565561 in words is "six billion, five hundred sixty-six million, five hundred sixty-five thousand, five hundred sixty-one".