821329 has 2 divisors, whose sum is σ = 821330. Its totient is φ = 821328.

The previous prime is 821311. The next prime is 821333. The reversal of 821329 is 923128.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 819025 + 2304 = 905^2 + 48^2 .

It is a cyclic number.

It is not a de Polignac number, because 821329 - 2⁵ = 821297 is a prime.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (822329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410664 + 410665.

It is an arithmetic number, because the mean of its divisors is an integer number (410665).

2⁸²¹³²⁹ is an apocalyptic number.

It is an amenable number.

821329 is a deficient number, since it is larger than the sum of its proper divisors (1).

821329 is an equidigital number, since it uses as much as digits as its factorization.

821329 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 821329 is about 906.2720342149. The cubic root of 821329 is about 93.6495552356.

The spelling of 821329 in words is "eight hundred twenty-one thousand, three hundred twenty-nine".