821039 has 2 divisors, whose sum is σ = 821040. Its totient is φ = 821038.

The previous prime is 821027. The next prime is 821053. The reversal of 821039 is 930128.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-821039 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821069) 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 as a sum of consecutive naturals, namely, 410519 + 410520.

It is an arithmetic number, because the mean of its divisors is an integer number (410520).

2⁸²¹⁰³⁹ is an apocalyptic number.

821039 is a deficient number, since it is larger than the sum of its proper divisors (1).

821039 is an equidigital number, since it uses as much as digits as its factorization.

821039 is an odious number, because the sum of its binary digits is odd.

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

The square root of 821039 is about 906.1120239794. The cubic root of 821039 is about 93.6385318138.

The spelling of 821039 in words is "eight hundred twenty-one thousand, thirty-nine".