8304721 has 4 divisors (see below), whose sum is σ = 8793252. Its totient is φ = 7816192.

The previous prime is 8304713. The next prime is 8304733. The reversal of 8304721 is 1274038.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7485696 + 819025 = 2736^2 + 905^2 .

It is not a de Polignac number, because 8304721 - 2³ = 8304713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8304421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244240 + ... + 244273.

It is an arithmetic number, because the mean of its divisors is an integer number (2198313).

Almost surely, 2^8304721 is an apocalyptic number.

It is an amenable number.

8304721 is a deficient number, since it is larger than the sum of its proper divisors (488531).

8304721 is a wasteful number, since it uses less digits than its factorization.

8304721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488530.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 8304721 is about 2881.7912832126. The cubic root of 8304721 is about 202.5077657947.

Adding to 8304721 its reverse (1274038), we get a palindrome (9578759).

It can be divided in two parts, 8304 and 721, that added together give a square (9025 = 95²).

The spelling of 8304721 in words is "eight million, three hundred four thousand, seven hundred twenty-one".