655656585656561 has 2 divisors, whose sum is σ = 655656585656562. Its totient is φ = 655656585656560.

The previous prime is 655656585656549. The next prime is 655656585656617. The reversal of 655656585656561 is 165656585656556.

655656585656561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 637021305396961 + 18635280259600 = 25239281^2 + 4316860^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655656585656561 is a prime.

It is not a weakly prime, because it can be changed into another prime (655656585656531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327828292828280 + 327828292828281.

It is an arithmetic number, because the mean of its divisors is an integer number (327828292828281).

Almost surely, 2^{655656585656561} is an apocalyptic number.

It is an amenable number.

655656585656561 is a deficient number, since it is larger than the sum of its proper divisors (1).

655656585656561 is an equidigital number, since it uses as much as digits as its factorization.

655656585656561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29160000000, while the sum is 80.

The spelling of 655656585656561 in words is "six hundred fifty-five trillion, six hundred fifty-six billion, five hundred eighty-five million, six hundred fifty-six thousand, five hundred sixty-one".