218317513 has 2 divisors, whose sum is σ = 218317514. Its totient is φ = 218317512.

The previous prime is 218317511. The next prime is 218317537. The reversal of 218317513 is 315713812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 206123449 + 12194064 = 14357^2 + 3492^2 .

It is a cyclic number.

It is not a de Polignac number, because 218317513 - 2¹ = 218317511 is a prime.

Together with 218317511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (218317511) 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, 109158756 + 109158757.

It is an arithmetic number, because the mean of its divisors is an integer number (109158757).

Almost surely, 2^218317513 is an apocalyptic number.

It is an amenable number.

218317513 is a deficient number, since it is larger than the sum of its proper divisors (1).

218317513 is an equidigital number, since it uses as much as digits as its factorization.

218317513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 31.

The square root of 218317513 is about 14775.5714948695. The cubic root of 218317513 is about 602.1382163699.

The spelling of 218317513 in words is "two hundred eighteen million, three hundred seventeen thousand, five hundred thirteen".