644327105 has 4 divisors (see below), whose sum is σ = 773192532. Its totient is φ = 515461680.

The previous prime is 644327077. The next prime is 644327153. The reversal of 644327105 is 501723446.

644327105 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 86564416 + 557762689 = 9304^2 + 23617^2 .

It is not a de Polignac number, because 644327105 - 2⁶ = 644327041 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64432706 + ... + 64432715.

It is an arithmetic number, because the mean of its divisors is an integer number (193298133).

Almost surely, 2^644327105 is an apocalyptic number.

It is an amenable number.

644327105 is a deficient number, since it is larger than the sum of its proper divisors (128865427).

644327105 is a wasteful number, since it uses less digits than its factorization.

644327105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128865426.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 644327105 is about 25383.5991340866. The cubic root of 644327105 is about 863.7116955207.

The spelling of 644327105 in words is "six hundred forty-four million, three hundred twenty-seven thousand, one hundred five".