656487668677 has 2 divisors, whose sum is σ = 656487668678. Its totient is φ = 656487668676.

The previous prime is 656487668657. The next prime is 656487668687. The reversal of 656487668677 is 776866784656.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 638774986756 + 17712681921 = 799234^2 + 133089^2 .

It is a cyclic number.

It is not a de Polignac number, because 656487668677 - 2⁷ = 656487668549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656487668647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328243834338 + 328243834339.

It is an arithmetic number, because the mean of its divisors is an integer number (328243834339).

Almost surely, 2^656487668677 is an apocalyptic number.

It is an amenable number.

656487668677 is a deficient number, since it is larger than the sum of its proper divisors (1).

656487668677 is an equidigital number, since it uses as much as digits as its factorization.

656487668677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3413975040, while the sum is 76.

The spelling of 656487668677 in words is "six hundred fifty-six billion, four hundred eighty-seven million, six hundred sixty-eight thousand, six hundred seventy-seven".