518321 has 4 divisors (see below), whose sum is σ = 519792. Its totient is φ = 516852.

The previous prime is 518311. The next prime is 518327. The reversal of 518321 is 123815.

518321 is nontrivially palindromic in base 14.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 123815 = 5 ⋅24763.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-518321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 518293 and 518302.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 518321.

It is not an unprimeable number, because it can be changed into a prime (518327) 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, 146 + ... + 1028.

It is an arithmetic number, because the mean of its divisors is an integer number (129948).

2⁵¹⁸³²¹ is an apocalyptic number.

It is an amenable number.

518321 is a deficient number, since it is larger than the sum of its proper divisors (1471).

518321 is an equidigital number, since it uses as much as digits as its factorization.

518321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1470.

The product of its digits is 240, while the sum is 20.

The square root of 518321 is about 719.9451367986. The cubic root of 518321 is about 80.3278731542.

The spelling of 518321 in words is "five hundred eighteen thousand, three hundred twenty-one".