1818198356257 has 2 divisors, whose sum is σ = 1818198356258. Its totient is φ = 1818198356256.

The previous prime is 1818198356159. The next prime is 1818198356297. The reversal of 1818198356257 is 7526538918181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1607966019136 + 210232337121 = 1268056^2 + 458511^2 .

It is an emirp because it is prime and its reverse (7526538918181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1818198356257 - 2¹⁹ = 1818197831969 is a prime.

It is not a weakly prime, because it can be changed into another prime (1818198356297) 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, 909099178128 + 909099178129.

It is an arithmetic number, because the mean of its divisors is an integer number (909099178129).

Almost surely, 2^{1818198356257} is an apocalyptic number.

It is an amenable number.

1818198356257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1818198356257 is an equidigital number, since it uses as much as digits as its factorization.

1818198356257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29030400, while the sum is 64.

The spelling of 1818198356257 in words is "one trillion, eight hundred eighteen billion, one hundred ninety-eight million, three hundred fifty-six thousand, two hundred fifty-seven".