8556221 has 4 divisors (see below), whose sum is σ = 8659392. Its totient is φ = 8453052.

The previous prime is 8556211. The next prime is 8556241. The reversal of 8556221 is 1226558.

8556221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1226558 = 2 ⋅613279.

It is not a de Polignac number, because 8556221 - 2⁶ = 8556157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8556211) 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, 51461 + ... + 51626.

It is an arithmetic number, because the mean of its divisors is an integer number (2164848).

Almost surely, 2^8556221 is an apocalyptic number.

It is an amenable number.

8556221 is a deficient number, since it is larger than the sum of its proper divisors (103171).

8556221 is a wasteful number, since it uses less digits than its factorization.

8556221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103170.

The product of its digits is 4800, while the sum is 29.

The square root of 8556221 is about 2925.1018785677. The cubic root of 8556221 is about 204.5317171530.

The spelling of 8556221 in words is "eight million, five hundred fifty-six thousand, two hundred twenty-one".