643484868 has 48 divisors (see below), whose sum is σ = 1619493120. Its totient is φ = 197685504.

The previous prime is 643484861. The next prime is 643484899. The reversal of 643484868 is 868484346.

It is a self number, because there is not a number n which added to its sum of digits gives 643484868.

It is not an unprimeable number, because it can be changed into a prime (643484861) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109296 + ... + 115032.

It is an arithmetic number, because the mean of its divisors is an integer number (33739440).

Almost surely, 2^643484868 is an apocalyptic number.

It is an amenable number.

643484868 is an abundant number, since it is smaller than the sum of its proper divisors (976008252).

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

643484868 is a wasteful number, since it uses less digits than its factorization.

643484868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6476 (or 6474 counting only the distinct ones).

The product of its digits is 3538944, while the sum is 51.

The square root of 643484868 is about 25367.0035282057. The cubic root of 643484868 is about 863.3351956881.

The spelling of 643484868 in words is "six hundred forty-three million, four hundred eighty-four thousand, eight hundred sixty-eight".