8643704981 has 2 divisors, whose sum is σ = 8643704982. Its totient is φ = 8643704980.

The previous prime is 8643704959. The next prime is 8643705001. The reversal of 8643704981 is 1894073468.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8542380625 + 101324356 = 92425^2 + 10066^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8643704981 is a prime.

It is a super-2 number, since 2×8643704981² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8643724981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4321852490 + 4321852491.

It is an arithmetic number, because the mean of its divisors is an integer number (4321852491).

Almost surely, 2^8643704981 is an apocalyptic number.

It is an amenable number.

8643704981 is a deficient number, since it is larger than the sum of its proper divisors (1).

8643704981 is an equidigital number, since it uses as much as digits as its factorization.

8643704981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1161216, while the sum is 50.

The square root of 8643704981 is about 92971.5277974929. The cubic root of 8643704981 is about 2052.2644009670.

The spelling of 8643704981 in words is "eight billion, six hundred forty-three million, seven hundred four thousand, nine hundred eighty-one".