8521968181 has 2 divisors, whose sum is σ = 8521968182. Its totient is φ = 8521968180.

The previous prime is 8521968163. The next prime is 8521968229. The reversal of 8521968181 is 1818691258.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6082596081 + 2439372100 = 77991^2 + 49390^2 .

It is a cyclic number.

It is not a de Polignac number, because 8521968181 - 2⁵ = 8521968149 is a prime.

It is a super-2 number, since 2×8521968181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8521968781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4260984090 + 4260984091.

It is an arithmetic number, because the mean of its divisors is an integer number (4260984091).

Almost surely, 2^8521968181 is an apocalyptic number.

It is an amenable number.

8521968181 is a deficient number, since it is larger than the sum of its proper divisors (1).

8521968181 is an equidigital number, since it uses as much as digits as its factorization.

8521968181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 276480, while the sum is 49.

The square root of 8521968181 is about 92314.5068827213. The cubic root of 8521968181 is about 2042.5842058862.

The spelling of 8521968181 in words is "eight billion, five hundred twenty-one million, nine hundred sixty-eight thousand, one hundred eighty-one".