218180571809 has 2 divisors, whose sum is σ = 218180571810. Its totient is φ = 218180571808.

The previous prime is 218180571793. The next prime is 218180571827. The reversal of 218180571809 is 908175081812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118011486784 + 100169085025 = 343528^2 + 316495^2 .

It is a cyclic number.

It is not a de Polignac number, because 218180571809 - 2⁴ = 218180571793 is a prime.

It is not a weakly prime, because it can be changed into another prime (218180571409) 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, 109090285904 + 109090285905.

It is an arithmetic number, because the mean of its divisors is an integer number (109090285905).

Almost surely, 2^218180571809 is an apocalyptic number.

It is an amenable number.

218180571809 is a deficient number, since it is larger than the sum of its proper divisors (1).

218180571809 is an equidigital number, since it uses as much as digits as its factorization.

218180571809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 322560, while the sum is 50.

The spelling of 218180571809 in words is "two hundred eighteen billion, one hundred eighty million, five hundred seventy-one thousand, eight hundred nine".