218018161 has 2 divisors, whose sum is σ = 218018162. Its totient is φ = 218018160.

The previous prime is 218018137. The next prime is 218018167. The reversal of 218018161 is 161810812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210830400 + 7187761 = 14520^2 + 2681^2 .

It is a cyclic number.

It is not a de Polignac number, because 218018161 - 2¹³ = 218009969 is a prime.

It is not a weakly prime, because it can be changed into another prime (218018167) 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, 109009080 + 109009081.

It is an arithmetic number, because the mean of its divisors is an integer number (109009081).

Almost surely, 2^218018161 is an apocalyptic number.

It is an amenable number.

218018161 is a deficient number, since it is larger than the sum of its proper divisors (1).

218018161 is an equidigital number, since it uses as much as digits as its factorization.

218018161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 28.

The square root of 218018161 is about 14765.4380564885. The cubic root of 218018161 is about 601.8628777508.

Adding to 218018161 its reverse (161810812), we get a palindrome (379828973).

The spelling of 218018161 in words is "two hundred eighteen million, eighteen thousand, one hundred sixty-one".