643488966 has 24 divisors (see below), whose sum is σ = 1395303624. Its totient is φ = 214330560.

The previous prime is 643488961. The next prime is 643488977. The reversal of 643488966 is 669884346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643488961) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11365 + ... + 37631.

It is an arithmetic number, because the mean of its divisors is an integer number (58137651).

Almost surely, 2^643488966 is an apocalyptic number.

643488966 is an abundant number, since it is smaller than the sum of its proper divisors (751814658).

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

643488966 is a wasteful number, since it uses less digits than its factorization.

643488966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27636 (or 27633 counting only the distinct ones).

The product of its digits is 5971968, while the sum is 54.

The square root of 643488966 is about 25367.0843023001. The cubic root of 643488966 is about 863.3370283860.

The spelling of 643488966 in words is "six hundred forty-three million, four hundred eighty-eight thousand, nine hundred sixty-six".