644784096 has 192 divisors, whose sum is σ = 1916006400. Its totient is φ = 188198400.

The previous prime is 644784071. The next prime is 644784113. The reversal of 644784096 is 690487446.

It is a Harshad number since it is a multiple of its sum of digits (48).

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 31 ways as a sum of consecutive naturals, for example, 4921951 + ... + 4922081.

It is an arithmetic number, because the mean of its divisors is an integer number (9979200).

Almost surely, 2^644784096 is an apocalyptic number.

644784096 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644784096, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (958003200).

644784096 is an abundant number, since it is smaller than the sum of its proper divisors (1271222304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644784096 is a wasteful number, since it uses less digits than its factorization.

644784096 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 48.

The square root of 644784096 is about 25392.5992367855. The cubic root of 644784096 is about 863.9158439980.

The spelling of 644784096 in words is "six hundred forty-four million, seven hundred eighty-four thousand, ninety-six".