218720413 has 2 divisors, whose sum is σ = 218720414. Its totient is φ = 218720412.

The previous prime is 218720393. The next prime is 218720417. The reversal of 218720413 is 314027812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165328164 + 53392249 = 12858^2 + 7307^2 .

It is a cyclic number.

It is not a de Polignac number, because 218720413 - 2⁹ = 218719901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218720417) 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, 109360206 + 109360207.

It is an arithmetic number, because the mean of its divisors is an integer number (109360207).

Almost surely, 2^218720413 is an apocalyptic number.

It is an amenable number.

218720413 is a deficient number, since it is larger than the sum of its proper divisors (1).

218720413 is an equidigital number, since it uses as much as digits as its factorization.

218720413 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 218720413 is about 14789.1992007681. The cubic root of 218720413 is about 602.5083995317.

The spelling of 218720413 in words is "two hundred eighteen million, seven hundred twenty thousand, four hundred thirteen".