643733 has 6 divisors (see below), whose sum is σ = 658242. Its totient is φ = 629520.

The previous prime is 643729. The next prime is 643751. The reversal of 643733 is 337346.

643733 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 529 + 643204 = 23^2 + 802^2 .

It is not a de Polignac number, because 643733 - 2² = 643729 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643703) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3635 + ... + 3807.

It is an arithmetic number, because the mean of its divisors is an integer number (109707).

2⁶⁴³⁷³³ is an apocalyptic number.

It is an amenable number.

643733 is a deficient number, since it is larger than the sum of its proper divisors (14509).

643733 is an equidigital number, since it uses as much as digits as its factorization.

643733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 234 counting only the distinct ones).

The product of its digits is 4536, while the sum is 26.

The square root of 643733 is about 802.3297327159. The cubic root of 643733 is about 86.3446150672.

The spelling of 643733 in words is "six hundred forty-three thousand, seven hundred thirty-three".