12644019440649 has 9 divisors (see below), whose sum is σ = 18263599045159. Its totient is φ = 8429339182080.

The previous prime is 12644019440641. The next prime is 12644019440653. The reversal of 12644019440649 is 94604491044621.

It is a happy number.

The square root of 12644019440649 is 3555843.

It is a perfect power (a square), and thus also a powerful number.

12644019440649 is a `hidden beast` number, since 1 + 2 + 6 + 4 + 4 + 0 + 194 + 406 + 49 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1189314570249 + 11454704870400 = 1090557^2 + 3384480^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 12644019440649 - 2³ = 12644019440641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12644019440595 and 12644019440604.

It is not an unprimeable number, because it can be changed into a prime (12644019440641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10074889 + ... + 11260169.

Almost surely, 2^{12644019440649} is an apocalyptic number.

12644019440649 is the 3555843-rd square number.

12644019440649 is the 1777922-nd centered octagonal number.

It is an amenable number.

12644019440649 is a deficient number, since it is larger than the sum of its proper divisors (5619579604510).

12644019440649 is an frugal number, since it uses more digits than its factorization.

12644019440649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2370568 (or 1185284 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 54.

The spelling of 12644019440649 in words is "twelve trillion, six hundred forty-four billion, nineteen million, four hundred forty thousand, six hundred forty-nine".