6681089561 has 2 divisors, whose sum is σ = 6681089562. Its totient is φ = 6681089560.

The previous prime is 6681089521. The next prime is 6681089579. The reversal of 6681089561 is 1659801866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3502272400 + 3178817161 = 59180^2 + 56381^2 .

It is a cyclic number.

It is not a de Polignac number, because 6681089561 - 2⁶ = 6681089497 is a prime.

It is not a weakly prime, because it can be changed into another prime (6681089521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3340544780 + 3340544781.

It is an arithmetic number, because the mean of its divisors is an integer number (3340544781).

Almost surely, 2^6681089561 is an apocalyptic number.

It is an amenable number.

6681089561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6681089561 is an equidigital number, since it uses as much as digits as its factorization.

6681089561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 50.

The square root of 6681089561 is about 81737.9322040875. The cubic root of 6681089561 is about 1883.4283264866.

The spelling of 6681089561 in words is "six billion, six hundred eighty-one million, eighty-nine thousand, five hundred sixty-one".