644782984 has 16 divisors (see below), whose sum is σ = 1250657100. Its totient is φ = 311274432.

The previous prime is 644782973. The next prime is 644782991. The reversal of 644782984 is 489287446.

644782984 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 565964100 + 78818884 = 23790^2 + 8878^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1389387 + ... + 1389850.

Almost surely, 2^644782984 is an apocalyptic number.

It is an amenable number.

644782984 is a deficient number, since it is larger than the sum of its proper divisors (605874116).

644782984 is a wasteful number, since it uses less digits than its factorization.

644782984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2779272 (or 2779268 counting only the distinct ones).

The product of its digits is 3096576, while the sum is 52.

The square root of 644782984 is about 25392.5773406324. The cubic root of 644782984 is about 863.9153473589.

The spelling of 644782984 in words is "six hundred forty-four million, seven hundred eighty-two thousand, nine hundred eighty-four".