644124563 has 4 divisors (see below), whose sum is σ = 659104248. Its totient is φ = 629144880.

The previous prime is 644124557. The next prime is 644124583. The reversal of 644124563 is 365421446.

644124563 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 is a cyclic number.

It is not a de Polignac number, because 644124563 - 2¹⁰ = 644123539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644124583) 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, 7489778 + ... + 7489863.

It is an arithmetic number, because the mean of its divisors is an integer number (164776062).

Almost surely, 2^644124563 is an apocalyptic number.

644124563 is a deficient number, since it is larger than the sum of its proper divisors (14979685).

644124563 is a wasteful number, since it uses less digits than its factorization.

644124563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14979684.

The product of its digits is 69120, while the sum is 35.

The square root of 644124563 is about 25379.6091971488. The cubic root of 644124563 is about 863.6211844400.

The spelling of 644124563 in words is "six hundred forty-four million, one hundred twenty-four thousand, five hundred sixty-three".