644583307 has 2 divisors, whose sum is σ = 644583308. Its totient is φ = 644583306.

The previous prime is 644583283. The next prime is 644583323. The reversal of 644583307 is 703385446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644583307 - 2¹⁹ = 644059019 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644583307.

It is not a weakly prime, because it can be changed into another prime (644583347) 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, 322291653 + 322291654.

It is an arithmetic number, because the mean of its divisors is an integer number (322291654).

Almost surely, 2^644583307 is an apocalyptic number.

644583307 is a deficient number, since it is larger than the sum of its proper divisors (1).

644583307 is an equidigital number, since it uses as much as digits as its factorization.

644583307 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 40.

The square root of 644583307 is about 25388.6452375860. The cubic root of 644583307 is about 863.8261587796.

The spelling of 644583307 in words is "six hundred forty-four million, five hundred eighty-three thousand, three hundred seven".