56666666657 has 2 divisors, whose sum is σ = 56666666658. Its totient is φ = 56666666656.

The previous prime is 56666666587. The next prime is 56666666669. The reversal of 56666666657 is 75666666665.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33682893841 + 22983772816 = 183529^2 + 151604^2 .

It is a cyclic number.

It is not a de Polignac number, because 56666666657 - 2¹⁸ = 56666404513 is a prime.

It is a super-2 number, since 2×56666666657² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 56666666593 and 56666666602.

It is not a weakly prime, because it can be changed into another prime (56666666857) 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 as a sum of consecutive naturals, namely, 28333333328 + 28333333329.

It is an arithmetic number, because the mean of its divisors is an integer number (28333333329).

Almost surely, 2^56666666657 is an apocalyptic number.

It is an amenable number.

56666666657 is a deficient number, since it is larger than the sum of its proper divisors (1).

56666666657 is an equidigital number, since it uses as much as digits as its factorization.

56666666657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 293932800, while the sum is 65.

The spelling of 56666666657 in words is "fifty-six billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred fifty-seven".