320981 has 4 divisors (see below), whose sum is σ = 325452. Its totient is φ = 316512.

The previous prime is 320953. The next prime is 321007. The reversal of 320981 is 189023.

320981 is nontrivially palindromic in base 13.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 189023 = 17 ⋅11119.

It can be written as a sum of positive squares in 2 ways, for example, as 168100 + 152881 = 410^2 + 391^2 .

It is a cyclic number.

It is not a de Polignac number, because 320981 - 2¹⁴ = 304597 is a prime.

It is a super-2 number, since 2×320981² = 206057604722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 320981.

It is not an unprimeable number, because it can be changed into a prime (320911) 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 in 3 ways as a sum of consecutive naturals, for example, 2126 + ... + 2271.

It is an arithmetic number, because the mean of its divisors is an integer number (81363).

2³²⁰⁹⁸¹ is an apocalyptic number.

It is an amenable number.

320981 is a deficient number, since it is larger than the sum of its proper divisors (4471).

320981 is an equidigital number, since it uses as much as digits as its factorization.

320981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4470.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 320981 is about 566.5518511134. The cubic root of 320981 is about 68.4688618311.

The spelling of 320981 in words is "three hundred twenty thousand, nine hundred eighty-one".