7989320681 has 2 divisors, whose sum is σ = 7989320682. Its totient is φ = 7989320680.

The previous prime is 7989320623. The next prime is 7989320683. The reversal of 7989320681 is 1860239897.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7906055056 + 83265625 = 88916^2 + 9125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7989320681 is a prime.

It is a super-2 number, since 2×7989320681² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 7989320683, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7989320683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3994660340 + 3994660341.

It is an arithmetic number, because the mean of its divisors is an integer number (3994660341).

Almost surely, 2^7989320681 is an apocalyptic number.

It is an amenable number.

7989320681 is a deficient number, since it is larger than the sum of its proper divisors (1).

7989320681 is an equidigital number, since it uses as much as digits as its factorization.

7989320681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1306368, while the sum is 53.

The square root of 7989320681 is about 89382.9999552488. Note that the first 4 decimals coincide. The cubic root of 7989320681 is about 1999.1096604566.

The spelling of 7989320681 in words is "seven billion, nine hundred eighty-nine million, three hundred twenty thousand, six hundred eighty-one".