18968678857 has 2 divisors, whose sum is σ = 18968678858. Its totient is φ = 18968678856.

The previous prime is 18968678843. The next prime is 18968678957. The reversal of 18968678857 is 75887686981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14308705161 + 4659973696 = 119619^2 + 68264^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18968678857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18968678857.

It is not a weakly prime, because it can be changed into another prime (18968678837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9484339428 + 9484339429.

It is an arithmetic number, because the mean of its divisors is an integer number (9484339429).

Almost surely, 2^18968678857 is an apocalyptic number.

It is an amenable number.

18968678857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18968678857 is an equidigital number, since it uses as much as digits as its factorization.

18968678857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 325140480, while the sum is 73.

The spelling of 18968678857 in words is "eighteen billion, nine hundred sixty-eight million, six hundred seventy-eight thousand, eight hundred fifty-seven".