8487221 has 2 divisors, whose sum is σ = 8487222. Its totient is φ = 8487220.

The previous prime is 8487217. The next prime is 8487223. The reversal of 8487221 is 1227848.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4431025 + 4056196 = 2105^2 + 2014^2 .

It is a cyclic number.

It is not a de Polignac number, because 8487221 - 2² = 8487217 is a prime.

It is a Sophie Germain prime.

Together with 8487223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8487223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4243610 + 4243611.

It is an arithmetic number, because the mean of its divisors is an integer number (4243611).

Almost surely, 2^8487221 is an apocalyptic number.

It is an amenable number.

8487221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8487221 is an equidigital number, since it uses as much as digits as its factorization.

8487221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7168, while the sum is 32.

The square root of 8487221 is about 2913.2835426714. The cubic root of 8487221 is about 203.9804303283.

The spelling of 8487221 in words is "eight million, four hundred eighty-seven thousand, two hundred twenty-one".