7681645513 has 2 divisors, whose sum is σ = 7681645514. Its totient is φ = 7681645512.

The previous prime is 7681645511. The next prime is 7681645553. The reversal of 7681645513 is 3155461867.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5735335824 + 1946309689 = 75732^2 + 44117^2 .

It is an emirp because it is prime and its reverse (3155461867) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7681645513 - 2¹ = 7681645511 is a prime.

Together with 7681645511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (7681645511) 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, 3840822756 + 3840822757.

It is an arithmetic number, because the mean of its divisors is an integer number (3840822757).

Almost surely, 2^7681645513 is an apocalyptic number.

It is an amenable number.

7681645513 is a deficient number, since it is larger than the sum of its proper divisors (1).

7681645513 is an equidigital number, since it uses as much as digits as its factorization.

7681645513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604800, while the sum is 46.

The square root of 7681645513 is about 87644.9970791260. The cubic root of 7681645513 is about 1973.1105585695.

The spelling of 7681645513 in words is "seven billion, six hundred eighty-one million, six hundred forty-five thousand, five hundred thirteen".