6644556161 has 2 divisors, whose sum is σ = 6644556162. Its totient is φ = 6644556160.

The previous prime is 6644556109. The next prime is 6644556169. The reversal of 6644556161 is 1616554466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6326611600 + 317944561 = 79540^2 + 17831^2 .

It is a cyclic number.

It is not a de Polignac number, because 6644556161 - 2²⁶ = 6577447297 is a prime.

It is not a weakly prime, because it can be changed into another prime (6644556169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322278080 + 3322278081.

It is an arithmetic number, because the mean of its divisors is an integer number (3322278081).

Almost surely, 2^6644556161 is an apocalyptic number.

It is an amenable number.

6644556161 is a deficient number, since it is larger than the sum of its proper divisors (1).

6644556161 is an equidigital number, since it uses as much as digits as its factorization.

6644556161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 518400, while the sum is 44.

The square root of 6644556161 is about 81514.1469991559. The cubic root of 6644556161 is about 1879.9890750271.

The spelling of 6644556161 in words is "six billion, six hundred forty-four million, five hundred fifty-six thousand, one hundred sixty-one".