7890056561 has 2 divisors, whose sum is σ = 7890056562. Its totient is φ = 7890056560.

The previous prime is 7890056519. The next prime is 7890056611. The reversal of 7890056561 is 1656500987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4256257600 + 3633798961 = 65240^2 + 60281^2 .

It is an emirp because it is prime and its reverse (1656500987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7890056561 - 2¹⁸ = 7889794417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7890056501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3945028280 + 3945028281.

It is an arithmetic number, because the mean of its divisors is an integer number (3945028281).

Almost surely, 2^7890056561 is an apocalyptic number.

It is an amenable number.

7890056561 is a deficient number, since it is larger than the sum of its proper divisors (1).

7890056561 is an equidigital number, since it uses as much as digits as its factorization.

7890056561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 453600, while the sum is 47.

The square root of 7890056561 is about 88825.9903462945. The cubic root of 7890056561 is about 1990.7957526459.

The spelling of 7890056561 in words is "seven billion, eight hundred ninety million, fifty-six thousand, five hundred sixty-one".