18679938647 has 2 divisors, whose sum is σ = 18679938648. Its totient is φ = 18679938646.

The previous prime is 18679938503. The next prime is 18679938649. The reversal of 18679938647 is 74683997681.

It is a strong prime.

It is an emirp because it is prime and its reverse (74683997681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18679938647 - 2¹⁸ = 18679676503 is a prime.

Together with 18679938649, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18679938649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9339969323 + 9339969324.

It is an arithmetic number, because the mean of its divisors is an integer number (9339969324).

Almost surely, 2^18679938647 is an apocalyptic number.

18679938647 is a deficient number, since it is larger than the sum of its proper divisors (1).

18679938647 is an equidigital number, since it uses as much as digits as its factorization.

18679938647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 109734912, while the sum is 68.

The spelling of 18679938647 in words is "eighteen billion, six hundred seventy-nine million, nine hundred thirty-eight thousand, six hundred forty-seven".