644304289 has 2 divisors, whose sum is σ = 644304290. Its totient is φ = 644304288.

The previous prime is 644304259. The next prime is 644304319. The reversal of 644304289 is 982403446.

644304289 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (644304259) and next prime (644304319).

It can be written as a sum of positive squares in only one way, i.e., 605553664 + 38750625 = 24608^2 + 6225^2 .

It is a cyclic number.

It is not a de Polignac number, because 644304289 - 2¹³ = 644296097 is a prime.

It is not a weakly prime, because it can be changed into another prime (644304209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322152144 + 322152145.

It is an arithmetic number, because the mean of its divisors is an integer number (322152145).

Almost surely, 2^644304289 is an apocalyptic number.

It is an amenable number.

644304289 is a deficient number, since it is larger than the sum of its proper divisors (1).

644304289 is an equidigital number, since it uses as much as digits as its factorization.

644304289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 644304289 is about 25383.1497060550. The cubic root of 644304289 is about 863.7015005548.

The spelling of 644304289 in words is "six hundred forty-four million, three hundred four thousand, two hundred eighty-nine".