56665661 has 8 divisors (see below), whose sum is σ = 61128480. Its totient is φ = 52217712.

The previous prime is 56665633. The next prime is 56665663. The reversal of 56665661 is 16656665.

56665661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 56665661 - 2¹⁸ = 56403517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56665663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4970 + ... + 11748.

It is an arithmetic number, because the mean of its divisors is an integer number (7641060).

Almost surely, 2^56665661 is an apocalyptic number.

It is an amenable number.

56665661 is a deficient number, since it is larger than the sum of its proper divisors (4462819).

56665661 is a wasteful number, since it uses less digits than its factorization.

56665661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7435.

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

The square root of 56665661 is about 7527.6597292917. The cubic root of 56665661 is about 384.0961786177.

It can be divided in two parts, 5 and 6665661, that added together give a palindrome (6665666).

The spelling of 56665661 in words is "fifty-six million, six hundred sixty-five thousand, six hundred sixty-one".