218101813 has 2 divisors, whose sum is σ = 218101814. Its totient is φ = 218101812.

The previous prime is 218101783. The next prime is 218101831. The reversal of 218101813 is 318101812.

Together with next prime (218101831) 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., 198049329 + 20052484 = 14073^2 + 4478^2 .

It is a cyclic number.

It is not a de Polignac number, because 218101813 - 2⁵ = 218101781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218101913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109050906 + 109050907.

It is an arithmetic number, because the mean of its divisors is an integer number (109050907).

Almost surely, 2^218101813 is an apocalyptic number.

It is an amenable number.

218101813 is a deficient number, since it is larger than the sum of its proper divisors (1).

218101813 is an equidigital number, since it uses as much as digits as its factorization.

218101813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 25.

The square root of 218101813 is about 14768.2704810008. The cubic root of 218101813 is about 601.9398447266.

Subtracting 218101813 from its reverse (318101812), we obtain a palindrome (99999999).

The spelling of 218101813 in words is "two hundred eighteen million, one hundred one thousand, eight hundred thirteen".