218418313 has 2 divisors, whose sum is σ = 218418314. Its totient is φ = 218418312.

The previous prime is 218418307. The next prime is 218418337. The reversal of 218418313 is 313814812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182574144 + 35844169 = 13512^2 + 5987^2 .

It is a cyclic number.

It is not a de Polignac number, because 218418313 - 2¹³ = 218410121 is a prime.

It is a super-3 number, since 3×218418313³ (a number of 26 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (218418383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109209156 + 109209157.

It is an arithmetic number, because the mean of its divisors is an integer number (109209157).

Almost surely, 2^218418313 is an apocalyptic number.

It is an amenable number.

218418313 is a deficient number, since it is larger than the sum of its proper divisors (1).

218418313 is an equidigital number, since it uses as much as digits as its factorization.

218418313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 31.

The square root of 218418313 is about 14778.9821368050. The cubic root of 218418313 is about 602.2308737606.

The spelling of 218418313 in words is "two hundred eighteen million, four hundred eighteen thousand, three hundred thirteen".