9278221 has 2 divisors, whose sum is σ = 9278222. Its totient is φ = 9278220.

The previous prime is 9278201. The next prime is 9278249. The reversal of 9278221 is 1228729.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8037225 + 1240996 = 2835^2 + 1114^2 .

It is a cyclic number.

It is not a de Polignac number, because 9278221 - 2¹¹ = 9276173 is a prime.

9278221 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9278201) 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 as a sum of consecutive naturals, namely, 4639110 + 4639111.

It is an arithmetic number, because the mean of its divisors is an integer number (4639111).

Almost surely, 2^9278221 is an apocalyptic number.

It is an amenable number.

9278221 is a deficient number, since it is larger than the sum of its proper divisors (1).

9278221 is an equidigital number, since it uses as much as digits as its factorization.

9278221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 31.

The square root of 9278221 is about 3046.0172356702. The cubic root of 9278221 is about 210.1300856898.

The spelling of 9278221 in words is "nine million, two hundred seventy-eight thousand, two hundred twenty-one".