321331 has 2 divisors, whose sum is σ = 321332. Its totient is φ = 321330.

The previous prime is 321329. The next prime is 321341. The reversal of 321331 is 133123.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 321331 - 2¹ = 321329 is a prime.

It is a super-2 number, since 2×321331² = 206507223122, which contains 22 as substring.

Together with 321329, it forms a pair of twin primes.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (321301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160665 + 160666.

It is an arithmetic number, because the mean of its divisors is an integer number (160666).

2³²¹³³¹ is an apocalyptic number.

321331 is a deficient number, since it is larger than the sum of its proper divisors (1).

321331 is an equidigital number, since it uses as much as digits as its factorization.

321331 is an odious number, because the sum of its binary digits is odd.

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

The square root of 321331 is about 566.8606530709. The cubic root of 321331 is about 68.4937391049.

Adding to 321331 its reverse (133123), we get a palindrome (454454).

The spelling of 321331 in words is "three hundred twenty-one thousand, three hundred thirty-one".