18540818449 has 2 divisors, whose sum is σ = 18540818450. Its totient is φ = 18540818448.

The previous prime is 18540818447. The next prime is 18540818497. The reversal of 18540818449 is 94481804581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15922654225 + 2618164224 = 126185^2 + 51168^2 .

It is a cyclic number.

It is not a de Polignac number, because 18540818449 - 2¹ = 18540818447 is a prime.

Together with 18540818447, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 18540818396 and 18540818405.

It is not a weakly prime, because it can be changed into another prime (18540818447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9270409224 + 9270409225.

It is an arithmetic number, because the mean of its divisors is an integer number (9270409225).

Almost surely, 2^18540818449 is an apocalyptic number.

It is an amenable number.

18540818449 is a deficient number, since it is larger than the sum of its proper divisors (1).

18540818449 is an equidigital number, since it uses as much as digits as its factorization.

18540818449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1474560, while the sum is 52.

The spelling of 18540818449 in words is "eighteen billion, five hundred forty million, eight hundred eighteen thousand, four hundred forty-nine".