8509221 has 24 divisors (see below), whose sum is σ = 14503424. Its totient is φ = 4704480.

The previous prime is 8509219. The next prime is 8509229. The reversal of 8509221 is 1229058.

It is not a de Polignac number, because 8509221 - 2¹ = 8509219 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 (8509229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 226 + ... + 4131.

Almost surely, 2^8509221 is an apocalyptic number.

It is an amenable number.

8509221 is a deficient number, since it is larger than the sum of its proper divisors (5994203).

8509221 is a wasteful number, since it uses less digits than its factorization.

8509221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4401 (or 4398 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 8509221 is about 2917.0569072269. The cubic root of 8509221 is about 204.1565263509.

The spelling of 8509221 in words is "eight million, five hundred nine thousand, two hundred twenty-one".