8647221 has 16 divisors (see below), whose sum is σ = 12768768. Its totient is φ = 5161200.

The previous prime is 8647193. The next prime is 8647229. The reversal of 8647221 is 1227468.

8647221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8647221 - 2⁶ = 8647157 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8647229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 256 + ... + 4166.

It is an arithmetic number, because the mean of its divisors is an integer number (798048).

Almost surely, 2^8647221 is an apocalyptic number.

It is an amenable number.

8647221 is a deficient number, since it is larger than the sum of its proper divisors (4121547).

8647221 is a wasteful number, since it uses less digits than its factorization.

8647221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3992.

The product of its digits is 5376, while the sum is 30.

The square root of 8647221 is about 2940.6157518452. The cubic root of 8647221 is about 205.2542631289.

The spelling of 8647221 in words is "eight million, six hundred forty-seven thousand, two hundred twenty-one".