643373668 has 48 divisors (see below), whose sum is σ = 1360643200. Its totient is φ = 260029440.

The previous prime is 643373663. The next prime is 643373677. The reversal of 643373668 is 866373346.

It is not an unprimeable number, because it can be changed into a prime (643373663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119188 + ... + 124468.

Almost surely, 2^643373668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643373668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (680321600).

643373668 is an abundant number, since it is smaller than the sum of its proper divisors (717269532).

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

643373668 is a wasteful number, since it uses less digits than its factorization.

643373668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5540 (or 5538 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 46.

The square root of 643373668 is about 25364.8116097873. The cubic root of 643373668 is about 863.2854621154.

The spelling of 643373668 in words is "six hundred forty-three million, three hundred seventy-three thousand, six hundred sixty-eight".