656343661 has 2 divisors, whose sum is σ = 656343662. Its totient is φ = 656343660.

The previous prime is 656343641. The next prime is 656343719. The reversal of 656343661 is 166343656.

656343661 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., 645414025 + 10929636 = 25405^2 + 3306^2 .

It is a cyclic number.

It is not a de Polignac number, because 656343661 - 2⁷ = 656343533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656343641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328171830 + 328171831.

It is an arithmetic number, because the mean of its divisors is an integer number (328171831).

Almost surely, 2^656343661 is an apocalyptic number.

It is an amenable number.

656343661 is a deficient number, since it is larger than the sum of its proper divisors (1).

656343661 is an equidigital number, since it uses as much as digits as its factorization.

656343661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 40.

The square root of 656343661 is about 25619.2049252119. The cubic root of 656343661 is about 869.0480012399.

The spelling of 656343661 in words is "six hundred fifty-six million, three hundred forty-three thousand, six hundred sixty-one".