218728897 has 2 divisors, whose sum is σ = 218728898. Its totient is φ = 218728896.

The previous prime is 218728847. The next prime is 218728921. The reversal of 218728897 is 798827812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156650256 + 62078641 = 12516^2 + 7879^2 .

It is a cyclic number.

It is not a de Polignac number, because 218728897 - 2¹⁵ = 218696129 is a prime.

It is not a weakly prime, because it can be changed into another prime (218728847) 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, 109364448 + 109364449.

It is an arithmetic number, because the mean of its divisors is an integer number (109364449).

Almost surely, 2^218728897 is an apocalyptic number.

It is an amenable number.

218728897 is a deficient number, since it is larger than the sum of its proper divisors (1).

218728897 is an equidigital number, since it uses as much as digits as its factorization.

218728897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 903168, while the sum is 52.

The square root of 218728897 is about 14789.4860289329. The cubic root of 218728897 is about 602.5161897132.

The spelling of 218728897 in words is "two hundred eighteen million, seven hundred twenty-eight thousand, eight hundred ninety-seven".