12644553643 has 2 divisors, whose sum is σ = 12644553644. Its totient is φ = 12644553642.

The previous prime is 12644553629. The next prime is 12644553653. The reversal of 12644553643 is 34635544621.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12644553643 - 2¹³ = 12644545451 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12644553643.

It is not a weakly prime, because it can be changed into another prime (12644553653) 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, 6322276821 + 6322276822.

It is an arithmetic number, because the mean of its divisors is an integer number (6322276822).

Almost surely, 2^12644553643 is an apocalyptic number.

12644553643 is a deficient number, since it is larger than the sum of its proper divisors (1).

12644553643 is an equidigital number, since it uses as much as digits as its factorization.

12644553643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1036800, while the sum is 43.

The spelling of 12644553643 in words is "twelve billion, six hundred forty-four million, five hundred fifty-three thousand, six hundred forty-three".