644316796 has 36 divisors (see below), whose sum is σ = 1222004448. Its totient is φ = 296095744.

The previous prime is 644316793. The next prime is 644316817. The reversal of 644316796 is 697613446.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644316793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1434780 + ... + 1435228.

It is an arithmetic number, because the mean of its divisors is an integer number (33944568).

Almost surely, 2^644316796 is an apocalyptic number.

It is an amenable number.

644316796 is a deficient number, since it is larger than the sum of its proper divisors (577687652).

644316796 is a wasteful number, since it uses less digits than its factorization.

644316796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 966 (or 515 counting only the distinct ones).

The product of its digits is 653184, while the sum is 46.

The square root of 644316796 is about 25383.3960690842. The cubic root of 644316796 is about 863.7070891382.

The spelling of 644316796 in words is "six hundred forty-four million, three hundred sixteen thousand, seven hundred ninety-six".