644306323 has 2 divisors, whose sum is σ = 644306324. Its totient is φ = 644306322.

The previous prime is 644306317. The next prime is 644306329. The reversal of 644306323 is 323603446.

It is a balanced prime because it is at equal distance from previous prime (644306317) and next prime (644306329).

It is a cyclic number.

It is not a de Polignac number, because 644306323 - 2¹⁷ = 644175251 is a prime.

It is not a weakly prime, because it can be changed into another prime (644306329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322153161 + 322153162.

It is an arithmetic number, because the mean of its divisors is an integer number (322153162).

Almost surely, 2^644306323 is an apocalyptic number.

644306323 is a deficient number, since it is larger than the sum of its proper divisors (1).

644306323 is an equidigital number, since it uses as much as digits as its factorization.

644306323 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 31.

The square root of 644306323 is about 25383.1897719731. The cubic root of 644306323 is about 863.7024094250.

Adding to 644306323 its reverse (323603446), we get a palindrome (967909769).

The spelling of 644306323 in words is "six hundred forty-four million, three hundred six thousand, three hundred twenty-three".