5566665561 has 4 divisors (see below), whose sum is σ = 7422220752. Its totient is φ = 3711110372.

The previous prime is 5566665557. The next prime is 5566665563. The reversal of 5566665561 is 1655666655.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 5566665561 - 2² = 5566665557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (5566665563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 927777591 + ... + 927777596.

It is an arithmetic number, because the mean of its divisors is an integer number (1855555188).

Almost surely, 2^5566665561 is an apocalyptic number.

It is an amenable number.

5566665561 is a deficient number, since it is larger than the sum of its proper divisors (1855555191).

5566665561 is a wasteful number, since it uses less digits than its factorization.

5566665561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1855555190.

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

The square root of 5566665561 is about 74610.0902090327. The cubic root of 5566665561 is about 1772.2774434286.

The spelling of 5566665561 in words is "five billion, five hundred sixty-six million, six hundred sixty-five thousand, five hundred sixty-one".