209868289 has 2 divisors, whose sum is σ = 209868290. Its totient is φ = 209868288.

The previous prime is 209868283. The next prime is 209868293. The reversal of 209868289 is 982868902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202578289 + 7290000 = 14233^2 + 2700^2 .

It is a cyclic number.

It is not a de Polignac number, because 209868289 - 2⁵ = 209868257 is a prime.

It is not a weakly prime, because it can be changed into another prime (209868283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104934144 + 104934145.

It is an arithmetic number, because the mean of its divisors is an integer number (104934145).

Almost surely, 2^209868289 is an apocalyptic number.

It is an amenable number.

209868289 is a deficient number, since it is larger than the sum of its proper divisors (1).

209868289 is an equidigital number, since it uses as much as digits as its factorization.

209868289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 995328, while the sum is 52.

The square root of 209868289 is about 14486.8315721555. The cubic root of 209868289 is about 594.2679026360.

The spelling of 209868289 in words is "two hundred nine million, eight hundred sixty-eight thousand, two hundred eighty-nine".