643344 has 40 divisors (see below), whose sum is σ = 1791552. Its totient is φ = 197760.

The previous prime is 643303. The next prime is 643369. The reversal of 643344 is 443346.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 643344.

It is an unprimeable number.

643344 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109 + ... + 1139.

2⁶⁴³³⁴⁴ 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 643344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (895776).

643344 is an abundant number, since it is smaller than the sum of its proper divisors (1148208).

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

643344 is a wasteful number, since it uses less digits than its factorization.

643344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1055 (or 1049 counting only the distinct ones).

The product of its digits is 3456, while the sum is 24.

The square root of 643344 is about 802.0872770466. The cubic root of 643344 is about 86.3272192301.

The spelling of 643344 in words is "six hundred forty-three thousand, three hundred forty-four".