6656216129 has 2 divisors, whose sum is σ = 6656216130. Its totient is φ = 6656216128.

The previous prime is 6656216041. The next prime is 6656216141. The reversal of 6656216129 is 9216126566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5516478529 + 1139737600 = 74273^2 + 33760^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6656216129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6656216129.

It is not a weakly prime, because it can be changed into another prime (6656216729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3328108064 + 3328108065.

It is an arithmetic number, because the mean of its divisors is an integer number (3328108065).

Almost surely, 2^6656216129 is an apocalyptic number.

It is an amenable number.

6656216129 is a deficient number, since it is larger than the sum of its proper divisors (1).

6656216129 is an equidigital number, since it uses as much as digits as its factorization.

6656216129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 44.

The square root of 6656216129 is about 81585.6367812374. The cubic root of 6656216129 is about 1881.0881101972.

The spelling of 6656216129 in words is "six billion, six hundred fifty-six million, two hundred sixteen thousand, one hundred twenty-nine".