6550129661 has 2 divisors, whose sum is σ = 6550129662. Its totient is φ = 6550129660.

The previous prime is 6550129657. The next prime is 6550129679. The reversal of 6550129661 is 1669210556.

6550129661 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., 6424824025 + 125305636 = 80155^2 + 11194^2 .

It is a cyclic number.

It is not a de Polignac number, because 6550129661 - 2² = 6550129657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6550129561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3275064830 + 3275064831.

It is an arithmetic number, because the mean of its divisors is an integer number (3275064831).

Almost surely, 2^6550129661 is an apocalyptic number.

It is an amenable number.

6550129661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6550129661 is an equidigital number, since it uses as much as digits as its factorization.

6550129661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 97200, while the sum is 41.

The square root of 6550129661 is about 80932.8713255621. The cubic root of 6550129661 is about 1871.0409773120.

The spelling of 6550129661 in words is "six billion, five hundred fifty million, one hundred twenty-nine thousand, six hundred sixty-one".