8638864181 has 2 divisors, whose sum is σ = 8638864182. Its totient is φ = 8638864180.

The previous prime is 8638864151. The next prime is 8638864207. The reversal of 8638864181 is 1814688368.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6293883556 + 2344980625 = 79334^2 + 48425^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8638864181 is a prime.

It is a super-2 number, since 2×8638864181² (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 (8638864151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4319432090 + 4319432091.

It is an arithmetic number, because the mean of its divisors is an integer number (4319432091).

Almost surely, 2^8638864181 is an apocalyptic number.

It is an amenable number.

8638864181 is a deficient number, since it is larger than the sum of its proper divisors (1).

8638864181 is an equidigital number, since it uses as much as digits as its factorization.

8638864181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1769472, while the sum is 53.

The square root of 8638864181 is about 92945.4903747352. The cubic root of 8638864181 is about 2051.8812143322.

The spelling of 8638864181 in words is "eight billion, six hundred thirty-eight million, eight hundred sixty-four thousand, one hundred eighty-one".