6644684449 has 4 divisors (see below), whose sum is σ = 7155814036. Its totient is φ = 6133554864.

The previous prime is 6644684441. The next prime is 6644684461. The reversal of 6644684449 is 9444864466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9444864466 = 2 ⋅4722432233.

It can be written as a sum of positive squares in 2 ways, for example, as 3366320400 + 3278364049 = 58020^2 + 57257^2 .

It is a cyclic number.

It is not a de Polignac number, because 6644684449 - 2³ = 6644684441 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6644684449.

It is not an unprimeable number, because it can be changed into a prime (6644684441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255564774 + ... + 255564799.

It is an arithmetic number, because the mean of its divisors is an integer number (1788953509).

Almost surely, 2^6644684449 is an apocalyptic number.

It is an amenable number.

6644684449 is a deficient number, since it is larger than the sum of its proper divisors (511129587).

6644684449 is a wasteful number, since it uses less digits than its factorization.

6644684449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511129586.

The product of its digits is 15925248, while the sum is 55.

The square root of 6644684449 is about 81514.9339017091. The cubic root of 6644684449 is about 1880.0011740788.

The spelling of 6644684449 in words is "six billion, six hundred forty-four million, six hundred eighty-four thousand, four hundred forty-nine".