18540818497 has 2 divisors, whose sum is σ = 18540818498. Its totient is φ = 18540818496.

The previous prime is 18540818449. The next prime is 18540818503. The reversal of 18540818497 is 79481804581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17289357121 + 1251461376 = 131489^2 + 35376^2 .

It is a cyclic number.

It is not a de Polignac number, because 18540818497 - 2⁷ = 18540818369 is a prime.

It is a super-3 number, since 3×18540818497³ (a number of 32 digits) contains 333 as substring.

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, 9270409248 + 9270409249.

It is an arithmetic number, because the mean of its divisors is an integer number (9270409249).

Almost surely, 2^18540818497 is an apocalyptic number.

It is an amenable number.

18540818497 is a deficient number, since it is larger than the sum of its proper divisors (1).

18540818497 is an equidigital number, since it uses as much as digits as its factorization.

18540818497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2580480, while the sum is 55.

The spelling of 18540818497 in words is "eighteen billion, five hundred forty million, eight hundred eighteen thousand, four hundred ninety-seven".