8321521 has 8 divisors (see below), whose sum is σ = 9271080. Its totient is φ = 7416192.

The previous prime is 8321519. The next prime is 8321527. The reversal of 8321521 is 1251238.

It can be written as a sum of positive squares in 4 ways, for example, as 2016400 + 6305121 = 1420^2 + 2511^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8321521 - 2¹ = 8321519 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8321492 and 8321501.

It is not an unprimeable number, because it can be changed into a prime (8321527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10660 + ... + 11413.

It is an arithmetic number, because the mean of its divisors is an integer number (1158885).

Almost surely, 2^8321521 is an apocalyptic number.

It is an amenable number.

8321521 is a deficient number, since it is larger than the sum of its proper divisors (949559).

8321521 is a wasteful number, since it uses less digits than its factorization.

8321521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22115.

The product of its digits is 480, while the sum is 22.

The square root of 8321521 is about 2884.7046642594. The cubic root of 8321521 is about 202.6442278919.

Adding to 8321521 its reverse (1251238), we get a palindrome (9572759).

It can be divided in two parts, 83215 and 21, that multiplied together give a triangular number (1747515 = T₁₈₆₉).

The spelling of 8321521 in words is "eight million, three hundred twenty-one thousand, five hundred twenty-one".