643840160 has 24 divisors (see below), whose sum is σ = 1521072756. Its totient is φ = 257536000.

The previous prime is 643840159. The next prime is 643840187. The reversal of 643840160 is 61048346.

It can be written as a sum of positive squares in 2 ways, for example, as 638876176 + 4963984 = 25276^2 + 2228^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2011841 + ... + 2012160.

Almost surely, 2^643840160 is an apocalyptic number.

It is an amenable number.

643840160 is an abundant number, since it is smaller than the sum of its proper divisors (877232596).

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

643840160 is a wasteful number, since it uses less digits than its factorization.

643840160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4024016 (or 4024008 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 643840160 is about 25374.0055962790. The cubic root of 643840160 is about 863.4940596425.

The spelling of 643840160 in words is "six hundred forty-three million, eight hundred forty thousand, one hundred sixty".