8507221 has 2 divisors, whose sum is σ = 8507222. Its totient is φ = 8507220.

The previous prime is 8507209. The next prime is 8507267. The reversal of 8507221 is 1227058.

8507221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7535025 + 972196 = 2745^2 + 986^2 .

It is a cyclic number.

It is not a de Polignac number, because 8507221 - 2¹⁷ = 8376149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8507281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4253610 + 4253611.

It is an arithmetic number, because the mean of its divisors is an integer number (4253611).

Almost surely, 2^8507221 is an apocalyptic number.

It is an amenable number.

8507221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8507221 is an equidigital number, since it uses as much as digits as its factorization.

8507221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 8507221 is about 2916.7140758052. The cubic root of 8507221 is about 204.1405301727.

The spelling of 8507221 in words is "eight million, five hundred seven thousand, two hundred twenty-one".