218404213 has 2 divisors, whose sum is σ = 218404214. Its totient is φ = 218404212.

The previous prime is 218404177. The next prime is 218404231. The reversal of 218404213 is 312404812.

Together with next prime (218404231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208022929 + 10381284 = 14423^2 + 3222^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218404213 is a prime.

It is a super-2 number, since 2×218404213² = 95400800512298738, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218404243) 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, 109202106 + 109202107.

It is an arithmetic number, because the mean of its divisors is an integer number (109202107).

Almost surely, 2^218404213 is an apocalyptic number.

It is an amenable number.

218404213 is a deficient number, since it is larger than the sum of its proper divisors (1).

218404213 is an equidigital number, since it uses as much as digits as its factorization.

218404213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 218404213 is about 14778.5051003138. The cubic root of 218404213 is about 602.2179144717.

The spelling of 218404213 in words is "two hundred eighteen million, four hundred four thousand, two hundred thirteen".