644700313 has 2 divisors, whose sum is σ = 644700314. Its totient is φ = 644700312.

The previous prime is 644700289. The next prime is 644700317. The reversal of 644700313 is 313007446.

644700313 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 644550544 + 149769 = 25388^2 + 387^2 .

It is a cyclic number.

It is not a de Polignac number, because 644700313 - 2⁹ = 644699801 is a prime.

It is not a weakly prime, because it can be changed into another prime (644700317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322350156 + 322350157.

It is an arithmetic number, because the mean of its divisors is an integer number (322350157).

Almost surely, 2^644700313 is an apocalyptic number.

It is an amenable number.

644700313 is a deficient number, since it is larger than the sum of its proper divisors (1).

644700313 is an equidigital number, since it uses as much as digits as its factorization.

644700313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 28.

The square root of 644700313 is about 25390.9494308504. The cubic root of 644700313 is about 863.8784234119.

Adding to 644700313 its reverse (313007446), we get a palindrome (957707759).

The spelling of 644700313 in words is "six hundred forty-four million, seven hundred thousand, three hundred thirteen".