56656661 has 4 divisors (see below), whose sum is σ = 56904300. Its totient is φ = 56409024.

The previous prime is 56656643. The next prime is 56656673. The reversal of 56656661 is 16665665.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16665665 = 5 ⋅3333133.

It can be written as a sum of positive squares in 2 ways, for example, as 54982225 + 1674436 = 7415^2 + 1294^2 .

It is a cyclic number.

It is not a de Polignac number, because 56656661 - 2¹⁰ = 56655637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56658661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123476 + ... + 123933.

It is an arithmetic number, because the mean of its divisors is an integer number (14226075).

Almost surely, 2^56656661 is an apocalyptic number.

It is an amenable number.

56656661 is a deficient number, since it is larger than the sum of its proper divisors (247639).

56656661 is a wasteful number, since it uses less digits than its factorization.

56656661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247638.

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

The square root of 56656661 is about 7527.0619102011. The cubic root of 56656661 is about 384.0758426765.

The spelling of 56656661 in words is "fifty-six million, six hundred fifty-six thousand, six hundred sixty-one".