8257221 has 20 divisors (see below), whose sum is σ = 14097952. Its totient is φ = 4718088.

The previous prime is 8257219. The next prime is 8257237. The reversal of 8257221 is 1227528.

It is not a de Polignac number, because 8257221 - 2¹ = 8257219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8257261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6715 + ... + 7848.

Almost surely, 2^8257221 is an apocalyptic number.

8257221 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

8257221 is a deficient number, since it is larger than the sum of its proper divisors (5840731).

8257221 is a wasteful number, since it uses less digits than its factorization.

8257221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14582 (or 14573 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 8257221 is about 2873.5380630853. The cubic root of 8257221 is about 202.1209369590.

The spelling of 8257221 in words is "eight million, two hundred fifty-seven thousand, two hundred twenty-one".