643289 has 4 divisors (see below), whose sum is σ = 657024. Its totient is φ = 629556.

The previous prime is 643273. The next prime is 643301. The reversal of 643289 is 982346.

643289 is nontrivially palindromic in base 16.

643289 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643289 - 2⁴ = 643273 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 643289.

It is not an unprimeable number, because it can be changed into a prime (643589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6797 + ... + 6890.

It is an arithmetic number, because the mean of its divisors is an integer number (164256).

2⁶⁴³²⁸⁹ is an apocalyptic number.

It is an amenable number.

643289 is a deficient number, since it is larger than the sum of its proper divisors (13735).

643289 is a wasteful number, since it uses less digits than its factorization.

643289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13734.

The product of its digits is 10368, while the sum is 32.

The square root of 643289 is about 802.0529907681. The cubic root of 643289 is about 86.3247590987.

The spelling of 643289 in words is "six hundred forty-three thousand, two hundred eighty-nine".