644046307 has 2 divisors, whose sum is σ = 644046308. Its totient is φ = 644046306.

The previous prime is 644046269. The next prime is 644046313. The reversal of 644046307 is 703640446.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644046307 is a prime.

It is not a weakly prime, because it can be changed into another prime (644046107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322023153 + 322023154.

It is an arithmetic number, because the mean of its divisors is an integer number (322023154).

Almost surely, 2^644046307 is an apocalyptic number.

644046307 is a deficient number, since it is larger than the sum of its proper divisors (1).

644046307 is an equidigital number, since it uses as much as digits as its factorization.

644046307 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 34.

The square root of 644046307 is about 25378.0674402130. The cubic root of 644046307 is about 863.5862086603.

The spelling of 644046307 in words is "six hundred forty-four million, forty-six thousand, three hundred seven".