7980816509 has 2 divisors, whose sum is σ = 7980816510. Its totient is φ = 7980816508.

The previous prime is 7980816499. The next prime is 7980816511. The reversal of 7980816509 is 9056180897.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5885191225 + 2095625284 = 76715^2 + 45778^2 .

It is a cyclic number.

It is not a de Polignac number, because 7980816509 - 2²⁰ = 7979767933 is a prime.

Together with 7980816511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7980816539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3990408254 + 3990408255.

It is an arithmetic number, because the mean of its divisors is an integer number (3990408255).

Almost surely, 2^7980816509 is an apocalyptic number.

It is an amenable number.

7980816509 is a deficient number, since it is larger than the sum of its proper divisors (1).

7980816509 is an equidigital number, since it uses as much as digits as its factorization.

7980816509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1088640, while the sum is 53.

The square root of 7980816509 is about 89335.4157599325. The cubic root of 7980816509 is about 1998.4000962453.

The spelling of 7980816509 in words is "seven billion, nine hundred eighty million, eight hundred sixteen thousand, five hundred nine".