8638221 has 8 divisors (see below), whose sum is σ = 11559744. Its totient is φ = 5737760.

The previous prime is 8638219. The next prime is 8638229. The reversal of 8638221 is 1228368.

8638221 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8638221 - 2¹ = 8638219 is a prime.

It is a super-3 number, since 3×8638221³ (a number of 22 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8638229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4281 + ... + 5966.

It is an arithmetic number, because the mean of its divisors is an integer number (1444968).

Almost surely, 2^8638221 is an apocalyptic number.

It is an amenable number.

8638221 is a deficient number, since it is larger than the sum of its proper divisors (2921523).

8638221 is a wasteful number, since it uses less digits than its factorization.

8638221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10531.

The product of its digits is 4608, while the sum is 30.

The square root of 8638221 is about 2939.0850617156. The cubic root of 8638221 is about 205.1830290826.

The spelling of 8638221 in words is "eight million, six hundred thirty-eight thousand, two hundred twenty-one".