644305703 has 2 divisors, whose sum is σ = 644305704. Its totient is φ = 644305702.

The previous prime is 644305691. The next prime is 644305709. The reversal of 644305703 is 307503446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644305703 - 2⁴ = 644305687 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644305703.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644305709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322152851 + 322152852.

It is an arithmetic number, because the mean of its divisors is an integer number (322152852).

Almost surely, 2^644305703 is an apocalyptic number.

644305703 is a deficient number, since it is larger than the sum of its proper divisors (1).

644305703 is an equidigital number, since it uses as much as digits as its factorization.

644305703 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 32.

The square root of 644305703 is about 25383.1775591631. The cubic root of 644305703 is about 863.7021323851.

The spelling of 644305703 in words is "six hundred forty-four million, three hundred five thousand, seven hundred three".