643928512 has 14 divisors (see below), whose sum is σ = 1277795768. Its totient is φ = 321964224.

The previous prime is 643928503. The next prime is 643928513. The reversal of 643928512 is 215829346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643928513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5030628 + ... + 5030755.

Almost surely, 2^643928512 is an apocalyptic number.

It is an amenable number.

643928512 is a deficient number, since it is larger than the sum of its proper divisors (633867256).

643928512 is a wasteful number, since it uses less digits than its factorization.

643928512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10061395 (or 10061385 counting only the distinct ones).

The product of its digits is 103680, while the sum is 40.

The square root of 643928512 is about 25375.7465308905. The cubic root of 643928512 is about 863.5335559556.

The spelling of 643928512 in words is "six hundred forty-three million, nine hundred twenty-eight thousand, five hundred twelve".