643388380 has 12 divisors (see below), whose sum is σ = 1351115640. Its totient is φ = 257355344.

The previous prime is 643388377. The next prime is 643388401. The reversal of 643388380 is 83883346.

643388380 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16084690 + ... + 16084729.

It is an arithmetic number, because the mean of its divisors is an integer number (112592970).

Almost surely, 2^643388380 is an apocalyptic number.

It is an amenable number.

643388380 is an abundant number, since it is smaller than the sum of its proper divisors (707727260).

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

643388380 is a wasteful number, since it uses less digits than its factorization.

643388380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32169428 (or 32169426 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 43.

The square root of 643388380 is about 25365.1016161970. The cubic root of 643388380 is about 863.2920423033.

The spelling of 643388380 in words is "six hundred forty-three million, three hundred eighty-eight thousand, three hundred eighty".