643824 has 60 divisors (see below), whose sum is σ = 1915056. Its totient is φ = 201216.

The previous prime is 643781. The next prime is 643847. The reversal of 643824 is 428346.

643824 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

643824 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2317 + ... + 2579.

2⁶⁴³⁸²⁴ 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 643824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (957528).

643824 is an abundant number, since it is smaller than the sum of its proper divisors (1271232).

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

643824 is a wasteful number, since it uses less digits than its factorization.

643824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 285 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 643824 is about 802.3864405634. The cubic root of 643824 is about 86.3486835189.

The spelling of 643824 in words is "six hundred forty-three thousand, eight hundred twenty-four".