8427221 has 4 divisors (see below), whose sum is σ = 9193344. Its totient is φ = 7661100.

The previous prime is 8427217. The next prime is 8427233. The reversal of 8427221 is 1227248.

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.

It is a cyclic number.

It is not a de Polignac number, because 8427221 - 2² = 8427217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8427271) 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, 383045 + ... + 383066.

It is an arithmetic number, because the mean of its divisors is an integer number (2298336).

Almost surely, 2^8427221 is an apocalyptic number.

It is an amenable number.

8427221 is a deficient number, since it is larger than the sum of its proper divisors (766123).

8427221 is a wasteful number, since it uses less digits than its factorization.

8427221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766122.

The product of its digits is 1792, while the sum is 26.

The square root of 8427221 is about 2902.9676195232. The cubic root of 8427221 is about 203.4986165433.

The spelling of 8427221 in words is "eight million, four hundred twenty-seven thousand, two hundred twenty-one".