8538225221 has 2 divisors, whose sum is σ = 8538225222. Its totient is φ = 8538225220.

The previous prime is 8538225193. The next prime is 8538225233. The reversal of 8538225221 is 1225228358.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7425268900 + 1112956321 = 86170^2 + 33361^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8538225221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8538225281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4269112610 + 4269112611.

It is an arithmetic number, because the mean of its divisors is an integer number (4269112611).

Almost surely, 2^8538225221 is an apocalyptic number.

It is an amenable number.

8538225221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8538225221 is an equidigital number, since it uses as much as digits as its factorization.

8538225221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 76800, while the sum is 38.

The square root of 8538225221 is about 92402.5173953610. The cubic root of 8538225221 is about 2043.8822346695.

The spelling of 8538225221 in words is "eight billion, five hundred thirty-eight million, two hundred twenty-five thousand, two hundred twenty-one".