56516661566 has 8 divisors (see below), whose sum is σ = 84791672640. Its totient is φ = 28252770688.

The previous prime is 56516661563. The next prime is 56516661583. The reversal of 56516661566 is 66516661565.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56516661563) 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 3 ways as a sum of consecutive naturals, for example, 2767331 + ... + 2787678.

It is an arithmetic number, because the mean of its divisors is an integer number (10598959080).

Almost surely, 2^56516661566 is an apocalyptic number.

56516661566 is a deficient number, since it is larger than the sum of its proper divisors (28275011074).

56516661566 is a wasteful number, since it uses less digits than its factorization.

56516661566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5560098.

The product of its digits is 5832000, while the sum is 53.

Subtracting 56516661566 from its reverse (66516661565), we obtain a palindrome (9999999999).

The spelling of 56516661566 in words is "fifty-six billion, five hundred sixteen million, six hundred sixty-one thousand, five hundred sixty-six".