644320118 has 16 divisors (see below), whose sum is σ = 1042100640. Its totient is φ = 297014016.

The previous prime is 644320097. The next prime is 644320123. The reversal of 644320118 is 811023446.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7046 + ... + 36582.

It is an arithmetic number, because the mean of its divisors is an integer number (65131290).

Almost surely, 2^644320118 is an apocalyptic number.

644320118 is a deficient number, since it is larger than the sum of its proper divisors (397780522).

644320118 is a wasteful number, since it uses less digits than its factorization.

644320118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30391.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 644320118 is about 25383.4615054764. The cubic root of 644320118 is about 863.7085735167.

The spelling of 644320118 in words is "six hundred forty-four million, three hundred twenty thousand, one hundred eighteen".