2644255661 has 2 divisors, whose sum is σ = 2644255662. Its totient is φ = 2644255660.

The previous prime is 2644255643. The next prime is 2644255723. The reversal of 2644255661 is 1665524462.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1440582025 + 1203673636 = 37955^2 + 34694^2 .

It is a cyclic number.

It is not a de Polignac number, because 2644255661 - 2¹⁰ = 2644254637 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 (2644255261) 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, 1322127830 + 1322127831.

It is an arithmetic number, because the mean of its divisors is an integer number (1322127831).

Almost surely, 2^2644255661 is an apocalyptic number.

It is an amenable number.

2644255661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2644255661 is an equidigital number, since it uses as much as digits as its factorization.

2644255661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 345600, while the sum is 41.

The square root of 2644255661 is about 51422.3264837366. The cubic root of 2644255661 is about 1382.8268841516.

The spelling of 2644255661 in words is "two billion, six hundred forty-four million, two hundred fifty-five thousand, six hundred sixty-one".