8186221 has 8 divisors (see below), whose sum is σ = 8387064. Its totient is φ = 7987200.

The previous prime is 8186219. The next prime is 8186251. The reversal of 8186221 is 1226818.

It can be written as a sum of positive squares in 4 ways, for example, as 5978025 + 2208196 = 2445^2 + 1486^2 .

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 8186221 - 2¹ = 8186219 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8186221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8186251) 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, 13321 + ... + 13921.

It is an arithmetic number, because the mean of its divisors is an integer number (1048383).

Almost surely, 2^8186221 is an apocalyptic number.

It is an amenable number.

8186221 is a deficient number, since it is larger than the sum of its proper divisors (200843).

8186221 is a wasteful number, since it uses less digits than its factorization.

8186221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911.

The product of its digits is 1536, while the sum is 28.

The square root of 8186221 is about 2861.1572833383. The cubic root of 8186221 is about 201.5399539431.

The spelling of 8186221 in words is "eight million, one hundred eighty-six thousand, two hundred twenty-one".