643894848 has 84 divisors (see below), whose sum is σ = 1876988880. Its totient is φ = 210982656.

The previous prime is 643894829. The next prime is 643894871. The reversal of 643894848 is 848498346.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 643894794 and 643894803.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24511 + ... + 43457.

Almost surely, 2^643894848 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643894848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (938494440).

643894848 is an abundant number, since it is smaller than the sum of its proper divisors (1233094032).

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

643894848 is a wasteful number, since it uses less digits than its factorization.

643894848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19024 (or 19011 counting only the distinct ones).

The product of its digits is 5308416, while the sum is 54.

The square root of 643894848 is about 25375.0832116862. The cubic root of 643894848 is about 863.5185074424.

The spelling of 643894848 in words is "six hundred forty-three million, eight hundred ninety-four thousand, eight hundred forty-eight".