331321 has 4 divisors (see below), whose sum is σ = 339444. Its totient is φ = 323200.

The previous prime is 331319. The next prime is 331333. The reversal of 331321 is 123133.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123133 = 59 ⋅2087.

It can be written as a sum of positive squares in 2 ways, for example, as 55696 + 275625 = 236^2 + 525^2 .

It is a cyclic number.

It is not a de Polignac number, because 331321 - 2¹ = 331319 is a prime.

It is a Duffinian number.

331321 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331301) 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, 4000 + ... + 4081.

It is an arithmetic number, because the mean of its divisors is an integer number (84861).

2³³¹³²¹ is an apocalyptic number.

It is an amenable number.

331321 is a deficient number, since it is larger than the sum of its proper divisors (8123).

331321 is an equidigital number, since it uses as much as digits as its factorization.

331321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8122.

The product of its digits is 54, while the sum is 13.

The square root of 331321 is about 575.6048992147. The cubic root of 331321 is about 69.1963183135.

Adding to 331321 its reverse (123133), we get a palindrome (454454).

It can be divided in two parts, 33132 and 1, that added together give a palindrome (33133).

The spelling of 331321 in words is "three hundred thirty-one thousand, three hundred twenty-one".