218332861 has 2 divisors, whose sum is σ = 218332862. Its totient is φ = 218332860.

The previous prime is 218332817. The next prime is 218332937. The reversal of 218332861 is 168233812.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166564836 + 51768025 = 12906^2 + 7195^2 .

It is a cyclic number.

It is not a de Polignac number, because 218332861 - 2⁷ = 218332733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218332661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109166430 + 109166431.

It is an arithmetic number, because the mean of its divisors is an integer number (109166431).

Almost surely, 2^218332861 is an apocalyptic number.

It is an amenable number.

218332861 is a deficient number, since it is larger than the sum of its proper divisors (1).

218332861 is an equidigital number, since it uses as much as digits as its factorization.

218332861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 34.

The square root of 218332861 is about 14776.0908565155. The cubic root of 218332861 is about 602.1523264011.

The spelling of 218332861 in words is "two hundred eighteen million, three hundred thirty-two thousand, eight hundred sixty-one".