8681221 has 2 divisors, whose sum is σ = 8681222. Its totient is φ = 8681220.

The previous prime is 8681213. The next prime is 8681243. The reversal of 8681221 is 1221868.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6076225 + 2604996 = 2465^2 + 1614^2 .

It is a cyclic number.

It is not a de Polignac number, because 8681221 - 2³ = 8681213 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8681221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8681251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4340610 + 4340611.

It is an arithmetic number, because the mean of its divisors is an integer number (4340611).

Almost surely, 2^8681221 is an apocalyptic number.

It is an amenable number.

8681221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8681221 is an equidigital number, since it uses as much as digits as its factorization.

8681221 is an evil number, because the sum of its binary digits is even.

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

The square root of 8681221 is about 2946.3911824468. The cubic root of 8681221 is about 205.5229243335.

The spelling of 8681221 in words is "eight million, six hundred eighty-one thousand, two hundred twenty-one".