218578013 has 2 divisors, whose sum is σ = 218578014. Its totient is φ = 218578012.

The previous prime is 218578007. The next prime is 218578081. The reversal of 218578013 is 310875812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 210888484 + 7689529 = 14522^2 + 2773^2 .

It is a cyclic number.

It is not a de Polignac number, because 218578013 - 2¹⁰ = 218576989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218578313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109289006 + 109289007.

It is an arithmetic number, because the mean of its divisors is an integer number (109289007).

Almost surely, 2^218578013 is an apocalyptic number.

It is an amenable number.

218578013 is a deficient number, since it is larger than the sum of its proper divisors (1).

218578013 is an equidigital number, since it uses as much as digits as its factorization.

218578013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 218578013 is about 14784.3840926837. The cubic root of 218578013 is about 602.3776148748.

The spelling of 218578013 in words is "two hundred eighteen million, five hundred seventy-eight thousand, thirteen".