208321 has 4 divisors (see below), whose sum is σ = 213444. Its totient is φ = 203200.

The previous prime is 208319. The next prime is 208333. The reversal of 208321 is 123802.

208321 = 4² + 5² + ... + 85².

It is a happy number.

208321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18225 + 190096 = 135^2 + 436^2 .

It is a cyclic number.

It is not a de Polignac number, because 208321 - 2¹ = 208319 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 208295 and 208304.

It is not an unprimeable number, because it can be changed into a prime (208391) 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, 2500 + ... + 2581.

It is an arithmetic number, because the mean of its divisors is an integer number (53361).

2²⁰⁸³²¹ is an apocalyptic number.

It is an amenable number.

208321 is a deficient number, since it is larger than the sum of its proper divisors (5123).

208321 is an equidigital number, since it uses as much as digits as its factorization.

208321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5122.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 208321 is about 456.4219538979. The cubic root of 208321 is about 59.2803852291.

It can be divided in two parts, 208 and 321, that added together give a square (529 = 23²).

The spelling of 208321 in words is "two hundred eight thousand, three hundred twenty-one".