643803 has 8 divisors (see below), whose sum is σ = 871488. Its totient is φ = 422664.

The previous prime is 643781. The next prime is 643847. The reversal of 643803 is 308346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643803 - 2⁸ = 643547 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (643873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1401 + ... + 1802.

It is an arithmetic number, because the mean of its divisors is an integer number (108936).

2⁶⁴³⁸⁰³ is an apocalyptic number.

643803 is a deficient number, since it is larger than the sum of its proper divisors (227685).

643803 is a wasteful number, since it uses less digits than its factorization.

643803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3273.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 643803 is about 802.3733544928. The cubic root of 643803 is about 86.3477446794.

The spelling of 643803 in words is "six hundred forty-three thousand, eight hundred three".