643819568 has 40 divisors (see below), whose sum is σ = 1427741952. Its totient is φ = 275508288.

The previous prime is 643819537. The next prime is 643819577. The reversal of 643819568 is 865918346.

643819568 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×643819568² = 829007272279413248, which contains 22 as substring.

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, 77471 + ... + 85377.

Almost surely, 2^643819568 is an apocalyptic number.

It is an amenable number.

643819568 is an abundant number, since it is smaller than the sum of its proper divisors (783922384).

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

643819568 is a wasteful number, since it uses less digits than its factorization.

643819568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8649 (or 8643 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 50.

The square root of 643819568 is about 25373.5998234385. The cubic root of 643819568 is about 863.4848538073.

The spelling of 643819568 in words is "six hundred forty-three million, eight hundred nineteen thousand, five hundred sixty-eight".