218242489 has 2 divisors, whose sum is σ = 218242490. Its totient is φ = 218242488.

The previous prime is 218242457. The next prime is 218242513. The reversal of 218242489 is 984242812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201498025 + 16744464 = 14195^2 + 4092^2 .

It is a cyclic number.

It is not a de Polignac number, because 218242489 - 2⁵ = 218242457 is a prime.

It is not a weakly prime, because it can be changed into another prime (218272489) 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, 109121244 + 109121245.

It is an arithmetic number, because the mean of its divisors is an integer number (109121245).

Almost surely, 2^218242489 is an apocalyptic number.

It is an amenable number.

218242489 is a deficient number, since it is larger than the sum of its proper divisors (1).

218242489 is an equidigital number, since it uses as much as digits as its factorization.

218242489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73728, while the sum is 40.

The square root of 218242489 is about 14773.0324916721. The cubic root of 218242489 is about 602.0692342826.

The spelling of 218242489 in words is "two hundred eighteen million, two hundred forty-two thousand, four hundred eighty-nine".