8561216449 has 2 divisors, whose sum is σ = 8561216450. Its totient is φ = 8561216448.

The previous prime is 8561216359. The next prime is 8561216497. The reversal of 8561216449 is 9446121658.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6432040000 + 2129176449 = 80200^2 + 46143^2 .

It is a cyclic number.

It is not a de Polignac number, because 8561216449 - 2⁹ = 8561215937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8561216399 and 8561216408.

It is not a weakly prime, because it can be changed into another prime (8561226449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4280608224 + 4280608225.

It is an arithmetic number, because the mean of its divisors is an integer number (4280608225).

Almost surely, 2^8561216449 is an apocalyptic number.

It is an amenable number.

8561216449 is a deficient number, since it is larger than the sum of its proper divisors (1).

8561216449 is an equidigital number, since it uses as much as digits as its factorization.

8561216449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 414720, while the sum is 46.

The square root of 8561216449 is about 92526.8417757788. The cubic root of 8561216449 is about 2045.7151388821.

The spelling of 8561216449 in words is "eight billion, five hundred sixty-one million, two hundred sixteen thousand, four hundred forty-nine".