18178749857 has 2 divisors, whose sum is σ = 18178749858. Its totient is φ = 18178749856.

The previous prime is 18178749793. The next prime is 18178749881. The reversal of 18178749857 is 75894787181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12625668496 + 5553081361 = 112364^2 + 74519^2 .

It is an emirp because it is prime and its reverse (75894787181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18178749857 - 2⁶ = 18178749793 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18178749793 and 18178749802.

It is not a weakly prime, because it can be changed into another prime (18178745857) 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, 9089374928 + 9089374929.

It is an arithmetic number, because the mean of its divisors is an integer number (9089374929).

Almost surely, 2^18178749857 is an apocalyptic number.

It is an amenable number.

18178749857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18178749857 is an equidigital number, since it uses as much as digits as its factorization.

18178749857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31610880, while the sum is 65.

The spelling of 18178749857 in words is "eighteen billion, one hundred seventy-eight million, seven hundred forty-nine thousand, eight hundred fifty-seven".