8120561 has 2 divisors, whose sum is σ = 8120562. Its totient is φ = 8120560.

The previous prime is 8120531. The next prime is 8120573. The reversal of 8120561 is 1650218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4243600 + 3876961 = 2060^2 + 1969^2 .

It is a cyclic number.

It is not a de Polignac number, because 8120561 - 2¹⁰ = 8119537 is a prime.

It is not a weakly prime, because it can be changed into another prime (8120531) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4060280 + 4060281.

It is an arithmetic number, because the mean of its divisors is an integer number (4060281).

Almost surely, 2^8120561 is an apocalyptic number.

It is an amenable number.

8120561 is a deficient number, since it is larger than the sum of its proper divisors (1).

8120561 is an equidigital number, since it uses as much as digits as its factorization.

8120561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 8120561 is about 2849.6598042573. The cubic root of 8120561 is about 200.9996699746. Note that the first 3 decimals are identical.

Adding to 8120561 its reverse (1650218), we get a palindrome (9770779).

The spelling of 8120561 in words is "eight million, one hundred twenty thousand, five hundred sixty-one".