643303808 has 64 divisors (see below), whose sum is σ = 1468432800. Its totient is φ = 274993152.

The previous prime is 643303799. The next prime is 643303841. The reversal of 643303808 is 808303346.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 498428 + ... + 499716.

Almost surely, 2^643303808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643303808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (734216400).

643303808 is an abundant number, since it is smaller than the sum of its proper divisors (825128992).

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

643303808 is a wasteful number, since it uses less digits than its factorization.

643303808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1867 (or 1855 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 643303808 is about 25363.4344677530. The cubic root of 643303808 is about 863.2542146935.

The spelling of 643303808 in words is "six hundred forty-three million, three hundred three thousand, eight hundred eight".