643400328 has 16 divisors (see below), whose sum is σ = 1608500880. Its totient is φ = 214466768.

The previous prime is 643400311. The next prime is 643400339. The reversal of 643400328 is 823004346.

It is a junction number, because it is equal to n+sod(n) for n = 643400295 and 643400304.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 13404150 + ... + 13404197.

It is an arithmetic number, because the mean of its divisors is an integer number (100531305).

Almost surely, 2^643400328 is an apocalyptic number.

It is an amenable number.

643400328 is an abundant number, since it is smaller than the sum of its proper divisors (965100552).

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

643400328 is a wasteful number, since it uses less digits than its factorization.

643400328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26808356 (or 26808352 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 643400328 is about 25365.3371355478. The cubic root of 643400328 is about 863.2973861722.

The spelling of 643400328 in words is "six hundred forty-three million, four hundred thousand, three hundred twenty-eight".