843221 has 4 divisors (see below), whose sum is σ = 852012. Its totient is φ = 834432.

The previous prime is 843211. The next prime is 843229. The reversal of 843221 is 122348.

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

It can be written as a sum of positive squares in 2 ways, for example, as 180625 + 662596 = 425^2 + 814^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-843221 is a prime.

It is a super-2 number, since 2×843221² = 1422043309682, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 843193 and 843202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (843229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4250 + ... + 4443.

It is an arithmetic number, because the mean of its divisors is an integer number (213003).

2⁸⁴³²²¹ is an apocalyptic number.

It is an amenable number.

843221 is a deficient number, since it is larger than the sum of its proper divisors (8791).

843221 is an equidigital number, since it uses as much as digits as its factorization.

843221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8790.

The product of its digits is 384, while the sum is 20.

The square root of 843221 is about 918.2706572683. The cubic root of 843221 is about 94.4743265177.

Adding to 843221 its reverse (122348), we get a palindrome (965569).

The spelling of 843221 in words is "eight hundred forty-three thousand, two hundred twenty-one".