643866848 has 12 divisors (see below), whose sum is σ = 1267612920. Its totient is φ = 321933408.

The previous prime is 643866809. The next prime is 643866871. The reversal of 643866848 is 848668346.

It is a self number, because there is not a number n which added to its sum of digits gives 643866848.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060388 + ... + 10060451.

It is an arithmetic number, because the mean of its divisors is an integer number (105634410).

Almost surely, 2^643866848 is an apocalyptic number.

It is an amenable number.

643866848 is a deficient number, since it is larger than the sum of its proper divisors (623746072).

643866848 is a wasteful number, since it uses less digits than its factorization.

643866848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20120849 (or 20120841 counting only the distinct ones).

The product of its digits is 5308416, while the sum is 53.

The square root of 643866848 is about 25374.5314833595. The cubic root of 643866848 is about 863.5059904562.

The spelling of 643866848 in words is "six hundred forty-three million, eight hundred sixty-six thousand, eight hundred forty-eight".