8666804521 has 2 divisors, whose sum is σ = 8666804522. Its totient is φ = 8666804520.

The previous prime is 8666804513. The next prime is 8666804669. The reversal of 8666804521 is 1254086668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5643014400 + 3023790121 = 75120^2 + 54989^2 .

It is a cyclic number.

It is not a de Polignac number, because 8666804521 - 2³ = 8666804513 is a prime.

It is a super-2 number, since 2×8666804521² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8666807521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4333402260 + 4333402261.

It is an arithmetic number, because the mean of its divisors is an integer number (4333402261).

Almost surely, 2^8666804521 is an apocalyptic number.

It is an amenable number.

8666804521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8666804521 is an equidigital number, since it uses as much as digits as its factorization.

8666804521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 552960, while the sum is 46.

The square root of 8666804521 is about 93095.6740187212. The cubic root of 8666804521 is about 2054.0909401087.

The spelling of 8666804521 in words is "eight billion, six hundred sixty-six million, eight hundred four thousand, five hundred twenty-one".