18384646393 has 2 divisors, whose sum is σ = 18384646394. Its totient is φ = 18384646392.

The previous prime is 18384646391. The next prime is 18384646403. The reversal of 18384646393 is 39364648381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12270657529 + 6113988864 = 110773^2 + 78192^2 .

It is a cyclic number.

It is not a de Polignac number, because 18384646393 - 2¹ = 18384646391 is a prime.

Together with 18384646391, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18384646391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9192323196 + 9192323197.

It is an arithmetic number, because the mean of its divisors is an integer number (9192323197).

Almost surely, 2^18384646393 is an apocalyptic number.

It is an amenable number.

18384646393 is a deficient number, since it is larger than the sum of its proper divisors (1).

18384646393 is an equidigital number, since it uses as much as digits as its factorization.

18384646393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8957952, while the sum is 55.

The spelling of 18384646393 in words is "eighteen billion, three hundred eighty-four million, six hundred forty-six thousand, three hundred ninety-three".