8191712779 has 2 divisors, whose sum is σ = 8191712780. Its totient is φ = 8191712778.

The previous prime is 8191712773. The next prime is 8191712873. The reversal of 8191712779 is 9772171918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8191712779 - 2⁹ = 8191712267 is a prime.

It is not a weakly prime, because it can be changed into another prime (8191712773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4095856389 + 4095856390.

It is an arithmetic number, because the mean of its divisors is an integer number (4095856390).

Almost surely, 2^8191712779 is an apocalyptic number.

8191712779 is a deficient number, since it is larger than the sum of its proper divisors (1).

8191712779 is an equidigital number, since it uses as much as digits as its factorization.

8191712779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 444528, while the sum is 52.

The square root of 8191712779 is about 90508.0812911201. The cubic root of 8191712779 is about 2015.8501199351.

The spelling of 8191712779 in words is "eight billion, one hundred ninety-one million, seven hundred twelve thousand, seven hundred seventy-nine".