643685274860 has 24 divisors (see below), whose sum is σ = 1380499485120. Its totient is φ = 251995937024.

The previous prime is 643685274853. The next prime is 643685274887. The reversal of 643685274860 is 68472586346.

It is a self number, because there is not a number n which added to its sum of digits gives 643685274860.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 342384845 + ... + 342386724.

It is an arithmetic number, because the mean of its divisors is an integer number (57520811880).

Almost surely, 2^643685274860 is an apocalyptic number.

It is an amenable number.

643685274860 is an abundant number, since it is smaller than the sum of its proper divisors (736814210260).

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

643685274860 is a wasteful number, since it uses less digits than its factorization.

643685274860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684771625 (or 684771623 counting only the distinct ones).

The product of its (nonzero) digits is 46448640, while the sum is 59.

The spelling of 643685274860 in words is "six hundred forty-three billion, six hundred eighty-five million, two hundred seventy-four thousand, eight hundred sixty".