8378221 has 4 divisors (see below), whose sum is σ = 8819200. Its totient is φ = 7937244.

The previous prime is 8378219. The next prime is 8378231. The reversal of 8378221 is 1228738.

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 8378221 - 2¹ = 8378219 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 (8378231) 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, 220461 + ... + 220498.

It is an arithmetic number, because the mean of its divisors is an integer number (2204800).

Almost surely, 2^8378221 is an apocalyptic number.

It is an amenable number.

8378221 is a deficient number, since it is larger than the sum of its proper divisors (440979).

8378221 is a wasteful number, since it uses less digits than its factorization.

8378221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440978.

The product of its digits is 5376, while the sum is 31.

The square root of 8378221 is about 2894.5156762402. The cubic root of 8378221 is about 203.1034360067.

The spelling of 8378221 in words is "eight million, three hundred seventy-eight thousand, two hundred twenty-one".