644304322 has 4 divisors (see below), whose sum is σ = 966456486. Its totient is φ = 322152160.

The previous prime is 644304319. The next prime is 644304371. The reversal of 644304322 is 223403446.

644304322 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 644093641 + 210681 = 25379^2 + 459^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161076079 + ... + 161076082.

Almost surely, 2^644304322 is an apocalyptic number.

644304322 is a deficient number, since it is larger than the sum of its proper divisors (322152164).

644304322 is a wasteful number, since it uses less digits than its factorization.

644304322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322152163.

The product of its (nonzero) digits is 13824, while the sum is 28.

The square root of 644304322 is about 25383.1503560925. The cubic root of 644304322 is about 863.7015153005.

Adding to 644304322 its reverse (223403446), we get a palindrome (867707768).

The spelling of 644304322 in words is "six hundred forty-four million, three hundred four thousand, three hundred twenty-two".