218358121 has 2 divisors, whose sum is σ = 218358122. Its totient is φ = 218358120.

The previous prime is 218358097. The next prime is 218358167. The reversal of 218358121 is 121853812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145443600 + 72914521 = 12060^2 + 8539^2 .

It is a cyclic number.

It is not a de Polignac number, because 218358121 - 2¹⁷ = 218227049 is a prime.

It is not a weakly prime, because it can be changed into another prime (218358191) 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, 109179060 + 109179061.

It is an arithmetic number, because the mean of its divisors is an integer number (109179061).

Almost surely, 2^218358121 is an apocalyptic number.

It is an amenable number.

218358121 is a deficient number, since it is larger than the sum of its proper divisors (1).

218358121 is an equidigital number, since it uses as much as digits as its factorization.

218358121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 31.

The square root of 218358121 is about 14776.9455910212. The cubic root of 218358121 is about 602.1755474914.

The spelling of 218358121 in words is "two hundred eighteen million, three hundred fifty-eight thousand, one hundred twenty-one".