644317247 has 8 divisors (see below), whose sum is σ = 739229856. Its totient is φ = 550121472.

The previous prime is 644317241. The next prime is 644317259. The reversal of 644317247 is 742713446.

644317247 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644317247 - 2⁴ = 644317231 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 644317247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644317241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 177278 + ... + 180875.

It is an arithmetic number, because the mean of its divisors is an integer number (92403732).

Almost surely, 2^644317247 is an apocalyptic number.

644317247 is a deficient number, since it is larger than the sum of its proper divisors (94912609).

644317247 is a wasteful number, since it uses less digits than its factorization.

644317247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358417.

The product of its digits is 112896, while the sum is 38.

The square root of 644317247 is about 25383.4049528427. The cubic root of 644317247 is about 863.7072906601.

The spelling of 644317247 in words is "six hundred forty-four million, three hundred seventeen thousand, two hundred forty-seven".