643920332 has 12 divisors (see below), whose sum is σ = 1229302536. Its totient is φ = 292691040.

The previous prime is 643920301. The next prime is 643920367. The reversal of 643920332 is 233029346.

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, 7317233 + ... + 7317320.

It is an arithmetic number, because the mean of its divisors is an integer number (102441878).

Almost surely, 2^643920332 is an apocalyptic number.

It is an amenable number.

643920332 is a deficient number, since it is larger than the sum of its proper divisors (585382204).

643920332 is a wasteful number, since it uses less digits than its factorization.

643920332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14634568 (or 14634566 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 32.

The square root of 643920332 is about 25375.5853528544. The cubic root of 643920332 is about 863.5298993725.

Adding to 643920332 its reverse (233029346), we get a palindrome (876949678).

The spelling of 643920332 in words is "six hundred forty-three million, nine hundred twenty thousand, three hundred thirty-two".