8116768721 has 2 divisors, whose sum is σ = 8116768722. Its totient is φ = 8116768720.

The previous prime is 8116768717. The next prime is 8116768757. The reversal of 8116768721 is 1278676118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7296576400 + 820192321 = 85420^2 + 28639^2 .

It is a cyclic number.

It is not a de Polignac number, because 8116768721 - 2² = 8116768717 is a prime.

It is not a weakly prime, because it can be changed into another prime (8116768771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4058384360 + 4058384361.

It is an arithmetic number, because the mean of its divisors is an integer number (4058384361).

Almost surely, 2^8116768721 is an apocalyptic number.

It is an amenable number.

8116768721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8116768721 is an equidigital number, since it uses as much as digits as its factorization.

8116768721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 225792, while the sum is 47.

The square root of 8116768721 is about 90093.1113959330. Note that the first 3 decimals coincide. The cubic root of 8116768721 is about 2009.6837634380.

The spelling of 8116768721 in words is "eight billion, one hundred sixteen million, seven hundred sixty-eight thousand, seven hundred twenty-one".