643211 has 4 divisors (see below), whose sum is σ = 645000. Its totient is φ = 641424.

The previous prime is 643199. The next prime is 643213. The reversal of 643211 is 112346.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643211 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 643211.

It is not an unprimeable number, because it can be changed into a prime (643213) 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, 146 + ... + 1143.

It is an arithmetic number, because the mean of its divisors is an integer number (161250).

2⁶⁴³²¹¹ is an apocalyptic number.

643211 is a deficient number, since it is larger than the sum of its proper divisors (1789).

643211 is a wasteful number, since it uses less digits than its factorization.

643211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1788.

The product of its digits is 144, while the sum is 17.

The square root of 643211 is about 802.0043640779. The cubic root of 643211 is about 86.3212699446.

Adding to 643211 its reverse (112346), we get a palindrome (755557).

The spelling of 643211 in words is "six hundred forty-three thousand, two hundred eleven".