321021 has 12 divisors (see below), whose sum is σ = 473148. Its totient is φ = 209664.

The previous prime is 321017. The next prime is 321031. The reversal of 321021 is 120123.

It is a happy number.

321021 is digitally balanced in base 7, 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 2 ways, for example, as 168921 + 152100 = 411^2 + 390^2 .

It is not a de Polignac number, because 321021 - 2² = 321017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

321021 is strictly pandigital in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 320994 and 321012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321031) 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 11 ways as a sum of consecutive naturals, for example, 141 + ... + 813.

It is an arithmetic number, because the mean of its divisors is an integer number (39429).

2³²¹⁰²¹ is an apocalyptic number.

It is an amenable number.

321021 is a deficient number, since it is larger than the sum of its proper divisors (152127).

321021 is a wasteful number, since it uses less digits than its factorization.

321021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732 (or 729 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 321021 is about 566.5871512839. The cubic root of 321021 is about 68.4717058631.

Adding to 321021 its reverse (120123), we get a palindrome (441144).

The spelling of 321021 in words is "three hundred twenty-one thousand, twenty-one", and thus it is an iban number.