8520321 has 12 divisors (see below), whose sum is σ = 11670032. Its totient is φ = 5526528.

The previous prime is 8520311. The next prime is 8520329. The reversal of 8520321 is 1230258.

It is not a de Polignac number, because 8520321 - 2⁵ = 8520289 is a prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as 8³ + 5³ + 2¹⁷ + 0 + 3 + 2²³ + 1 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8520329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33025 + ... + 33281.

Almost surely, 2^8520321 is an apocalyptic number.

It is an amenable number.

8520321 is a deficient number, since it is larger than the sum of its proper divisors (3149711).

8520321 is an equidigital number, since it uses as much as digits as its factorization.

8520321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 8520321 is about 2918.9588897413. The cubic root of 8520321 is about 204.2452596121.

Adding to 8520321 its reverse (1230258), we get a palindrome (9750579).

The spelling of 8520321 in words is "eight million, five hundred twenty thousand, three hundred twenty-one".