6688133561 has 2 divisors, whose sum is σ = 6688133562. Its totient is φ = 6688133560.

The previous prime is 6688133549. The next prime is 6688133587. The reversal of 6688133561 is 1653318866.

6688133561 is digitally balanced in base 3, 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., 6688131961 + 1600 = 81781^2 + 40^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6688133561 is a prime.

It is a super-2 number, since 2×6688133561² = 89462261059549081442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6688133531) 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, 3344066780 + 3344066781.

It is an arithmetic number, because the mean of its divisors is an integer number (3344066781).

Almost surely, 2^6688133561 is an apocalyptic number.

It is an amenable number.

6688133561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6688133561 is an equidigital number, since it uses as much as digits as its factorization.

6688133561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 622080, while the sum is 47.

The square root of 6688133561 is about 81781.0097822227. The cubic root of 6688133561 is about 1884.0900054555.

The spelling of 6688133561 in words is "six billion, six hundred eighty-eight million, one hundred thirty-three thousand, five hundred sixty-one".