218623117 has 2 divisors, whose sum is σ = 218623118. Its totient is φ = 218623116.

The previous prime is 218623103. The next prime is 218623147. The reversal of 218623117 is 711326812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209496676 + 9126441 = 14474^2 + 3021^2 .

It is a cyclic number.

It is not a de Polignac number, because 218623117 - 2¹⁵ = 218590349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218623147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109311558 + 109311559.

It is an arithmetic number, because the mean of its divisors is an integer number (109311559).

Almost surely, 2^218623117 is an apocalyptic number.

It is an amenable number.

218623117 is a deficient number, since it is larger than the sum of its proper divisors (1).

218623117 is an equidigital number, since it uses as much as digits as its factorization.

218623117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 31.

The square root of 218623117 is about 14785.9094072702. The cubic root of 218623117 is about 602.4190459576.

Adding to 218623117 its reverse (711326812), we get a palindrome (929949929).

The spelling of 218623117 in words is "two hundred eighteen million, six hundred twenty-three thousand, one hundred seventeen".