8338566721 has 2 divisors, whose sum is σ = 8338566722. Its totient is φ = 8338566720.

The previous prime is 8338566703. The next prime is 8338566739. The reversal of 8338566721 is 1276658338.

It is the 37280-th star number.

It is a balanced prime because it is at equal distance from previous prime (8338566703) and next prime (8338566739).

It can be written as a sum of positive squares in only one way, i.e., 8188259121 + 150307600 = 90489^2 + 12260^2 .

It is a cyclic number.

It is not a de Polignac number, because 8338566721 - 2¹⁷ = 8338435649 is a prime.

It is not a weakly prime, because it can be changed into another prime (8338566781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4169283360 + 4169283361.

It is an arithmetic number, because the mean of its divisors is an integer number (4169283361).

Almost surely, 2^8338566721 is an apocalyptic number.

It is an amenable number.

8338566721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8338566721 is an equidigital number, since it uses as much as digits as its factorization.

8338566721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 49.

The square root of 8338566721 is about 91315.7528633477. The cubic root of 8338566721 is about 2027.8249833241.

The spelling of 8338566721 in words is "eight billion, three hundred thirty-eight million, five hundred sixty-six thousand, seven hundred twenty-one".