8544721 has 4 divisors (see below), whose sum is σ = 8620452. Its totient is φ = 8468992.

The previous prime is 8544709. The next prime is 8544733. The reversal of 8544721 is 1274458.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1274458 = 2 ⋅637229.

It is an interprime number because it is at equal distance from previous prime (8544709) and next prime (8544733).

It can be written as a sum of positive squares in 2 ways, for example, as 921600 + 7623121 = 960^2 + 2761^2 .

It is a cyclic number.

It is not a de Polignac number, because 8544721 - 2⁷ = 8544593 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8544751) 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, 37696 + ... + 37921.

It is an arithmetic number, because the mean of its divisors is an integer number (2155113).

Almost surely, 2^8544721 is an apocalyptic number.

It is an amenable number.

8544721 is a deficient number, since it is larger than the sum of its proper divisors (75731).

8544721 is a wasteful number, since it uses less digits than its factorization.

8544721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75730.

The product of its digits is 8960, while the sum is 31.

The square root of 8544721 is about 2923.1354741099. The cubic root of 8544721 is about 204.4400423617.

The spelling of 8544721 in words is "eight million, five hundred forty-four thousand, seven hundred twenty-one".