18198542641 has 2 divisors, whose sum is σ = 18198542642. Its totient is φ = 18198542640.

The previous prime is 18198542639. The next prime is 18198542671. The reversal of 18198542641 is 14624589181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17844952225 + 353590416 = 133585^2 + 18804^2 .

It is a cyclic number.

It is not a de Polignac number, because 18198542641 - 2¹ = 18198542639 is a prime.

Together with 18198542639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18198542671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9099271320 + 9099271321.

It is an arithmetic number, because the mean of its divisors is an integer number (9099271321).

Almost surely, 2^18198542641 is an apocalyptic number.

It is an amenable number.

18198542641 is a deficient number, since it is larger than the sum of its proper divisors (1).

18198542641 is an equidigital number, since it uses as much as digits as its factorization.

18198542641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 552960, while the sum is 49.

The spelling of 18198542641 in words is "eighteen billion, one hundred ninety-eight million, five hundred forty-two thousand, six hundred forty-one".