8604721 has 4 divisors (see below), whose sum is σ = 8745844. Its totient is φ = 8463600.

The previous prime is 8604707. The next prime is 8604733. The reversal of 8604721 is 1274068.

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 3474496 + 5130225 = 1864^2 + 2265^2 .

It is a cyclic number.

It is not a de Polignac number, because 8604721 - 2⁵ = 8604689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8604721.

It is not an unprimeable number, because it can be changed into a prime (8604751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70470 + ... + 70591.

It is an arithmetic number, because the mean of its divisors is an integer number (2186461).

Almost surely, 2^8604721 is an apocalyptic number.

It is an amenable number.

8604721 is a deficient number, since it is larger than the sum of its proper divisors (141123).

8604721 is a wasteful number, since it uses less digits than its factorization.

8604721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141122.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 8604721 is about 2933.3804731061. The cubic root of 8604721 is about 204.9174444504.

Adding to 8604721 its reverse (1274068), we get a palindrome (9878789).

It can be divided in two parts, 86047 and 21, that added together give a palindrome (86068).

The spelling of 8604721 in words is "eight million, six hundred four thousand, seven hundred twenty-one".