56666561 has 8 divisors (see below), whose sum is σ = 66268224. Its totient is φ = 47441520.

The previous prime is 56666557. The next prime is 56666563. The reversal of 56666561 is 16566665.

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

It is not a de Polignac number, because 56666561 - 2² = 56666557 is a prime.

It is a super-2 number, since 2×56666561² = 6422198271133442, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (56666563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93830 + ... + 94431.

It is an arithmetic number, because the mean of its divisors is an integer number (8283528).

Almost surely, 2^56666561 is an apocalyptic number.

It is an amenable number.

56666561 is a deficient number, since it is larger than the sum of its proper divisors (9601663).

56666561 is a wasteful number, since it uses less digits than its factorization.

56666561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188311.

The product of its digits is 194400, while the sum is 41.

The square root of 56666561 is about 7527.7195085896. The cubic root of 56666561 is about 384.0982120933.

The spelling of 56666561 in words is "fifty-six million, six hundred sixty-six thousand, five hundred sixty-one".