321289 has 2 divisors, whose sum is σ = 321290. Its totient is φ = 321288.

The previous prime is 321247. The next prime is 321301. The reversal of 321289 is 982123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250000 + 71289 = 500^2 + 267^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321289 is a prime.

It is a d-powerful number, because it can be written as 3³ + 2² + 2¹⁸ + 1 + 8² + 9⁵ .

321289 is a lucky number.

It is equal to p₂₇₇₀₉ and since 321289 and 27709 have the same sum of digits, it is a Honaker prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 321289.

It is not a weakly prime, because it can be changed into another prime (321239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160644 + 160645.

It is an arithmetic number, because the mean of its divisors is an integer number (160645).

2³²¹²⁸⁹ is an apocalyptic number.

It is an amenable number.

321289 is a deficient number, since it is larger than the sum of its proper divisors (1).

321289 is an equidigital number, since it uses as much as digits as its factorization.

321289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 321289 is about 566.8236057187. The cubic root of 321289 is about 68.4907547861.

The spelling of 321289 in words is "three hundred twenty-one thousand, two hundred eighty-nine".