644702323 has 2 divisors, whose sum is σ = 644702324. Its totient is φ = 644702322.

The previous prime is 644702321. The next prime is 644702353. The reversal of 644702323 is 323207446.

644702323 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644702323 - 2¹ = 644702321 is a prime.

Together with 644702321, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (644702321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322351161 + 322351162.

It is an arithmetic number, because the mean of its divisors is an integer number (322351162).

Almost surely, 2^644702323 is an apocalyptic number.

644702323 is a deficient number, since it is larger than the sum of its proper divisors (1).

644702323 is an equidigital number, since it uses as much as digits as its factorization.

644702323 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 31.

The square root of 644702323 is about 25390.9890118522. The cubic root of 644702323 is about 863.8793211902.

Adding to 644702323 its reverse (323207446), we get a palindrome (967909769).

The spelling of 644702323 in words is "six hundred forty-four million, seven hundred two thousand, three hundred twenty-three".